wip

19 files changed, 373 insertions, 327 deletions

diff --git a/fluid/app/Snap_Action.cxx b/fluid/app/Snap_Action.cxx
index 2e30853d4..3e71d91c5 100644
--- a/fluid/app/Snap_Action.cxx
+++ b/fluid/app/Snap_Action.cxx
@@ -402,17 +402,18 @@ void Layout_Suite::read(fld::io::Project_Reader *in) {
  Also updates the FLUID user interface.
  */
 void Layout_Suite::update_label() {
-  std::string sym;
+  const char *sym = "";
   switch (storage_) {
-    case FLD_TOOL_STORE_INTERNAL: sym.assign("@fd_beaker  "); break;
-    case FLD_TOOL_STORE_USER: sym.assign("@fd_user  "); break;
-    case FLD_TOOL_STORE_PROJECT: sym.assign("@fd_project  "); break;
-    case FLD_TOOL_STORE_FILE: sym.assign("@fd_file  "); break;
+    case FLD_TOOL_STORE_INTERNAL: sym = "@fd_beaker  "; break;
+    case FLD_TOOL_STORE_USER: sym = "@fd_user  "; break;
+    case FLD_TOOL_STORE_PROJECT: sym = "@fd_project  "; break;
+    case FLD_TOOL_STORE_FILE: sym = "@fd_file  "; break;
   }
-  sym.append(name_);
+  char buf[256];
+  snprintf(buf, sizeof(buf), "%s%s", sym, name_ ? name_ : "");
   if (menu_label)
     ::free(menu_label);
-  menu_label = fl_strdup(sym.c_str());
+  menu_label = fl_strdup(buf);
   Fluid.layout_list->update_menu_labels();
 }
 
@@ -1082,7 +1083,7 @@ void Snap_Action::draw_all(Snap_Data &data) {
 
 /** Return a sensible step size for resizing a widget. */
 void Snap_Action::get_resize_stepsize(int &x_step, int &y_step) {
-  auto layout = Fluid.proj.layout;
+  Layout_Preset *layout = Fluid.proj.layout;
   if ((layout->widget_inc_w > 1) && (layout->widget_inc_h > 1)) {
     x_step = layout->widget_inc_w;
     y_step = layout->widget_inc_h;
@@ -1097,7 +1098,7 @@ void Snap_Action::get_resize_stepsize(int &x_step, int &y_step) {
 
 /** Return a sensible step size for moving a widget. */
 void Snap_Action::get_move_stepsize(int &x_step, int &y_step) {
-  auto layout = Fluid.proj.layout;
+  Layout_Preset *layout = Fluid.proj.layout;
   if ((layout->group_grid_x > 1) && (layout->group_grid_y > 1)) {
     x_step = layout->group_grid_x;
     y_step = layout->group_grid_y;
@@ -1112,7 +1113,7 @@ void Snap_Action::get_move_stepsize(int &x_step, int &y_step) {
 
 /** Fix the given size to the same or next bigger snap position. */
 void Snap_Action::better_size(int &w, int &h) {
-  auto layout = Fluid.proj.layout;
+  Layout_Preset *layout = Fluid.proj.layout;
   int x_min = 1, y_min = 1, x_inc = 1, y_inc = 1;
   get_resize_stepsize(x_inc, y_inc);
   if (x_inc < 1) x_inc = 1;
@@ -1427,13 +1428,13 @@ public:
 class Fd_Snap_Window_Grid : public Fd_Snap_Grid {
 public:
   void check(Snap_Data &d) override {
-    auto layout = Fluid.proj.layout;
+    Layout_Preset *layout = Fluid.proj.layout;
     clr();
     if (in_window(d)) check_grid(d, layout->left_window_margin, layout->window_grid_x, d.win->o->w()-layout->right_window_margin,
                                  layout->top_window_margin, layout->window_grid_y, d.win->o->h()-layout->bottom_window_margin);
   }
   void draw(Snap_Data &d) override {
-    auto layout = Fluid.proj.layout;
+    Layout_Preset *layout = Fluid.proj.layout;
     draw_grid(nearest_x, nearest_y, layout->window_grid_x, layout->window_grid_y);
   }
 };
@@ -1446,7 +1447,7 @@ class Fd_Snap_Group_Grid : public Fd_Snap_Grid {
 public:
   void check(Snap_Data &d) override {
     if (in_group(d)) {
-      auto layout = Fluid.proj.layout;
+      Layout_Preset *layout = Fluid.proj.layout;
       clr();
       Fl_Widget *g = parent(d);
       check_grid(d, g->x()+layout->left_group_margin, layout->group_grid_x, g->x()+g->w()-layout->right_group_margin,
@@ -1454,7 +1455,7 @@ public:
     }
   }
   void draw(Snap_Data &d) override {
-    auto layout = Fluid.proj.layout;
+    Layout_Preset *layout = Fluid.proj.layout;
     draw_grid(nearest_x, nearest_y, layout->group_grid_x, layout->group_grid_y);
   }
 };
@@ -1615,7 +1616,7 @@ class Fd_Snap_Widget_Ideal_Width : public Snap_Action {
 public:
   Fd_Snap_Widget_Ideal_Width() { type = 1; mask = FD_LEFT|FD_RIGHT; }
   void check(Snap_Data &d) override {
-    auto layout = Fluid.proj.layout;
+    Layout_Preset *layout = Fluid.proj.layout;
     clr();
     if (!d.wgt) return;
     int iw = 15, ih = 15;
@@ -1642,7 +1643,7 @@ class Fd_Snap_Widget_Ideal_Height : public Snap_Action {
 public:
   Fd_Snap_Widget_Ideal_Height() { type = 2; mask = FD_TOP|FD_BOTTOM; }
   void check(Snap_Data &d) override {
-    auto layout = Fluid.proj.layout;
+    Layout_Preset *layout = Fluid.proj.layout;
     clr();
     if (!d.wgt) return;
     int iw, ih;
diff --git a/fluid/io/Code_Writer.cxx b/fluid/io/Code_Writer.cxx
index 9460a6ac0..f451d187e 100644
--- a/fluid/io/Code_Writer.cxx
+++ b/fluid/io/Code_Writer.cxx
@@ -27,14 +27,12 @@
 
 #include <zlib.h>
 
-#include <string>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 using namespace fld;
 using namespace fld::io;
-using namespace fld::proj;
 
 // ---- Fd_Id_Map implementation ----
 
@@ -915,9 +913,9 @@ Code_Writer::~Code_Writer()
  \param[in] type FD_TAG_GENERIC, FD_TAG_CODE, FD_TAG_MENU_CALLBACK, or FD_TAG_WIDGET_CALLBACK
  \param[in] uid the unique id of the current type
  */
-void Code_Writer::tag(proj::Mergeback::Tag prev_type, proj::Mergeback::Tag next_type, unsigned short uid) {
+void Code_Writer::tag(Mergeback::Tag prev_type, Mergeback::Tag next_type, unsigned short uid) {
   if (proj_.write_mergeback_data) {
-    Mergeback::print_tag(code_file, prev_type, next_type, uid, (uint32_t)block_crc_);
+    ::Mergeback::print_tag(code_file, prev_type, next_type, uid, (uint32_t)block_crc_);
   }
   block_crc_ = crc32(0, 0, 0);
 }
diff --git a/fluid/io/Code_Writer.h b/fluid/io/Code_Writer.h
index f2ca32a3e..bd99395e5 100644
--- a/fluid/io/Code_Writer.h
+++ b/fluid/io/Code_Writer.h
@@ -25,7 +25,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <string>
 
 class Node;
 
@@ -157,7 +156,7 @@ public:
   int write_code(const char *cfile, const char *hfile, bool to_codeview=false);
   void write_public(int state); // writes pubic:/private: as needed
 
-  void tag(proj::Mergeback::Tag prev_type, proj::Mergeback::Tag next_type, unsigned short uid);
+  void tag(Mergeback::Tag prev_type, Mergeback::Tag next_type, unsigned short uid);
 
   static unsigned long block_crc(const void *data, int n=-1, unsigned long in_crc=0, bool *inout_line_start=0);
 };
diff --git a/fluid/io/Project_Writer.h b/fluid/io/Project_Writer.h
index 64769a762..845f77f1e 100644
--- a/fluid/io/Project_Writer.h
+++ b/fluid/io/Project_Writer.h
@@ -21,8 +21,6 @@
 
 #include <stdio.h>
 
-#include <string>
-
 class Node;
 
 namespace fld {
@@ -54,7 +52,6 @@ public:
   int write_project(const char *filename, int selected_only, bool codeview);
   void NewFunction();
   void write_word(const char *);
-  void write_word(const std::string& word) { write_word(word.c_str()); }
   void write_string(const char *,...) __fl_attr((__format__ (__printf__, 2, 3)));
   void write_indent(int n);
   void write_open();
diff --git a/fluid/io/String_Writer.cxx b/fluid/io/String_Writer.cxx
index 3066aa97b..97245697b 100644
--- a/fluid/io/String_Writer.cxx
+++ b/fluid/io/String_Writer.cxx
@@ -60,26 +60,29 @@ static int write_escaped_strings(FILE *out, const char *text) {
  \param[in] filename file path and name to a file that will hold the strings
  \return 1 if the file could not be opened for writing, or the result of `fclose`.
  */
-int fld::io::write_strings(Project &proj, const std::string &filename) {
+int fld::io::write_strings(Project &proj, const char *filename) {
   Node *p;
   Widget_Node *w;
   int i;
 
-  FILE *fp = fl_fopen(filename.c_str(), "wb");
+  FILE *fp = fl_fopen(filename, "wb");
   if (!fp) return 1;
 
   switch (proj.i18n.type) {
     case FLD_I18N_TYPE_NONE : /* None, just put static text out */
       fprintf(fp, "# generated by Fast Light User Interface Designer (fluid) version %.4f\n",
               FL_VERSION);
-      for (auto w: proj.tree.all_widgets()) {
-        if (w->label()) {
-          write_escaped_strings(fp, w->label());
-          putc('\n', fp);
-        }
-        if (!(!w->tooltip() || !w->tooltip()[0])) {
-          write_escaped_strings(fp, w->tooltip());
-          putc('\n', fp);
+      for (p = proj.tree.first; p; p = p->next) {
+        if (p->is_widget()) {
+          w = (Widget_Node *)p;
+          if (w->label()) {
+            write_escaped_strings(fp, w->label());
+            putc('\n', fp);
+          }
+          if (!(!w->tooltip() || !w->tooltip()[0])) {
+            write_escaped_strings(fp, w->tooltip());
+            putc('\n', fp);
+          }
         }
       }
       break;
diff --git a/fluid/io/String_Writer.h b/fluid/io/String_Writer.h
index 0109a32a3..8402836c1 100644
--- a/fluid/io/String_Writer.h
+++ b/fluid/io/String_Writer.h
@@ -17,15 +17,13 @@
 #ifndef FLUID_IO_STRING_WRITER_H
 #define FLUID_IO_STRING_WRITER_H
 
-#include <string>
-
 namespace fld {
 
 class Project;
 
 namespace io {
 
-int write_strings(Project &proj, const std::string &filename);
+int write_strings(Project &proj, const char *filename);
 
 } // namespace io
 } // namespace fld
diff --git a/fluid/nodes/Button_Node.cxx b/fluid/nodes/Button_Node.cxx
index d989c527c..877c5588d 100644
--- a/fluid/nodes/Button_Node.cxx
+++ b/fluid/nodes/Button_Node.cxx
@@ -57,7 +57,7 @@ Fl_Menu_Item *Button_Node::subtypes() {
 }
 
 void Button_Node::ideal_size(int &w, int &h) {
-  auto layout = Fluid.proj.layout;
+  fld::app::Layout_Preset *layout = Fluid.proj.layout;
   h = layout->labelsize + 8;
   w = layout->labelsize * 4 + 8;
   fld::app::Snap_Action::better_size(w, h);
@@ -95,7 +95,7 @@ void Button_Node::copy_properties() {
 // ---- Return Button ----
 
 void Return_Button_Node::ideal_size(int &w, int &h) {
-  auto layout = Fluid.proj.layout;
+  fld::app::Layout_Preset *layout = Fluid.proj.layout;
   h = layout->labelsize + 8;
   w = layout->labelsize * 4 + 8 + h; // make room for the symbol
   fld::app::Snap_Action::better_size(w, h);
@@ -120,7 +120,7 @@ Repeat_Button_Node Repeat_Button_Node::prototype;
 // ---- Light Button ----
 
 void Light_Button_Node::ideal_size(int &w, int &h) {
-  auto layout = Fluid.proj.layout;
+  fld::app::Layout_Preset *layout = Fluid.proj.layout;
   h = layout->labelsize + 8;
   w = layout->labelsize * 4 + 8 + layout->labelsize; // make room for the light
   fld::app::Snap_Action::better_size(w, h);
@@ -136,7 +136,7 @@ Light_Button_Node Light_Button_Node::prototype;
 // ---- Check Button ----
 
 void Check_Button_Node::ideal_size(int &w, int &h) {
-  auto layout = Fluid.proj.layout;
+  fld::app::Layout_Preset *layout = Fluid.proj.layout;
   h = layout->labelsize + 8;
   w = layout->labelsize * 4 + 8 + layout->labelsize; // make room for the symbol
   fld::app::Snap_Action::better_size(w, h);
@@ -152,7 +152,7 @@ Check_Button_Node Check_Button_Node::prototype;
 // ---- Round Button ----
 
 void Round_Button_Node::ideal_size(int &w, int &h) {
-  auto layout = Fluid.proj.layout;
+  fld::app::Layout_Preset *layout = Fluid.proj.layout;
   h = layout->labelsize + 8;
   w = layout->labelsize * 4 + 8 + layout->labelsize; // make room for the symbol
   fld::app::Snap_Action::better_size(w, h);
diff --git a/fluid/nodes/Function_Node.cxx b/fluid/nodes/Function_Node.cxx
index 27e8c83de..de3706eb3 100644
--- a/fluid/nodes/Function_Node.cxx
+++ b/fluid/nodes/Function_Node.cxx
@@ -185,6 +185,18 @@ const char *c_check(const char *c, int type) {
  or C++ function.
  */
 
+Function_Node::Function_Node() {
+  return_type_ = 0;
+  public_ = 0;
+  declare_c_ = 0;
+  constructor = 0;
+  havewidgets = 0;
+}
+
+Function_Node::~Function_Node() {
+  if (return_type_) free((void*)return_type_);
+}
+
 /// Prototype for a function to be used by the factory.
 Function_Node Function_Node::prototype;
 
@@ -204,7 +216,7 @@ Node *Function_Node::make(Strategy strategy) {
   }
   Function_Node *o = new Function_Node();
   o->name("make_window()");
-  o->return_type_.clear();
+  if (o->return_type_) { free((void*)o->return_type_); o->return_type_ = 0; }
   o->add(anchor, strategy);
   o->factory = this;
   o->public_ = 1;
@@ -225,7 +237,7 @@ void Function_Node::write_properties(fld::io::Project_Writer &f) {
     case 2: f.write_string("protected"); break;
   }
   if (declare_c_) f.write_string("C");
-  if (!return_type().empty()) {
+  if (return_type()[0]) {
     f.write_string("return_type");
     f.write_word(return_type());
   }
@@ -335,36 +347,41 @@ void Function_Node::write_code1(fld::io::Code_Writer& f) {
     if (havechildren)
       f.write_c("int main(int argc, char **argv) {\n");
   } else {
-    std::string rtype = return_type();
-    std::string star = "";
+    char rtype[256];
+    const char *star = "";
+    const char *rt = return_type();
+    strncpy(rtype, rt ? rt : "", sizeof(rtype)-1);
+    rtype[sizeof(rtype)-1] = '\0';
     // from matt: let the user type "static " at the start of type
     // in order to declare a static method;
     int is_static = 0;
     int is_virtual = 0;
-    if (!rtype.empty()) {
-      if (rtype == "static") {
+    if (rtype[0]) {
+      if (strcmp(rtype, "static") == 0) {
         is_static = 1;
-        rtype.clear();
-      } else if (rtype.compare(0, 7, "static ")==0) {
+        rtype[0] = '\0';
+      } else if (strncmp(rtype, "static ", 7)==0) {
         is_static = 1;
-        rtype.erase(0, 7);
+        memmove(rtype, rtype+7, strlen(rtype)-6);
       }
     }
-    if (!rtype.empty()) {
-      if (rtype == "virtual") {
+    if (rtype[0]) {
+      if (strcmp(rtype, "virtual") == 0) {
         is_virtual = 1;
-        rtype.clear();
-      } else if (rtype.compare(0, 8, "virtual ")==0) {
+        rtype[0] = '\0';
+      } else if (strncmp(rtype, "virtual ", 8)==0) {
         is_virtual = 1;
-        rtype.erase(0, 8);
+        memmove(rtype, rtype+8, strlen(rtype)-7);
       }
     }
-    if (rtype.empty()) {
+    if (!rtype[0]) {
       if (havewidgets) {
-        rtype = subclassname(child);
+        const char *scn = subclassname(child);
+        strncpy(rtype, scn ? scn : "", sizeof(rtype)-1);
+        rtype[sizeof(rtype)-1] = '\0';
         star = "*";
       } else {
-        rtype = "void";
+        strcpy(rtype, "void");
       }
     }
 
@@ -383,9 +400,9 @@ void Function_Node::write_code1(fld::io::Code_Writer& f) {
       if (is_static) f.write_h("static ");
       if (is_virtual) f.write_h("virtual ");
       if (!constructor) {
-        f.write_h("%s%s ", rtype.c_str(), star.c_str());
+        f.write_h("%s%s ", rtype, star);
         if (havechildren)
-          f.write_c("%s%s ", rtype.c_str(), star.c_str());
+          f.write_c("%s%s ", rtype, star);
       }
 
       // if this is a subclass, only f.write_h() the part before the ':'
@@ -416,9 +433,9 @@ void Function_Node::write_code1(fld::io::Code_Writer& f) {
         write_comment_c(f);
       if (public_==1) {
         if (declare_c_)
-          f.write_h("extern \"C\" { %s%s %s; }\n", rtype.c_str(), star.c_str(), name());
+          f.write_h("extern \"C\" { %s%s %s; }\n", rtype, star, name());
         else
-          f.write_h("%s%s %s;\n", rtype.c_str(), star.c_str(), name());
+          f.write_h("%s%s %s;\n", rtype, star, name());
       } else if (public_==2) {
         // write neither the prototype nor static, the function may be declared elsewhere
       } else {
@@ -430,7 +447,7 @@ void Function_Node::write_code1(fld::io::Code_Writer& f) {
       char s[1024];
       if (havechildren) {
         clean_function_for_implementation(s, name());
-        f.write_c("%s%s %s {\n", rtype.c_str(), star.c_str(), s);
+        f.write_c("%s%s %s {\n", rtype, star, s);
       }
     }
   }
@@ -459,7 +476,7 @@ void Function_Node::write_code2(fld::io::Code_Writer& f) {
       f.write_c("%s%s->show(argc, argv);\n", f.indent(1), var);
     if (havechildren)
       f.write_c("%sreturn Fl::run();\n", f.indent(1));
-  } else if (havewidgets && !constructor && return_type().empty()) {
+  } else if (havewidgets && !constructor && !return_type()[0]) {
     f.write_c("%sreturn %s;\n", f.indent(1), var);
   }
   if (havechildren)
@@ -474,11 +491,11 @@ void Function_Node::write_code2(fld::io::Code_Writer& f) {
  \return 1 if they match, 0 if not
  */
 int Function_Node::has_signature(const char *rtype, const char *sig) const {
-  if (rtype && return_type().empty())
+  if (rtype && !return_type()[0])
     return 0;
   if (!name())
     return 0;
-  if ( (rtype==0 || (return_type() == rtype)) && fl_filename_match(name(), sig)) {
+  if ( (rtype==0 || strcmp(return_type(), rtype)==0) && fl_filename_match(name(), sig)) {
     return 1;
   }
   return 0;
@@ -615,6 +632,14 @@ int Code_Node::handle_editor_changes() {
  \todo this node could support multiple lines of code for each block.
  */
 
+CodeBlock_Node::CodeBlock_Node() {
+  end_code_ = 0;
+}
+
+CodeBlock_Node::~CodeBlock_Node() {
+  if (end_code_) free((void*)end_code_);
+}
+
 /// Prototype for a block of code to be used by the factory.
 CodeBlock_Node CodeBlock_Node::prototype;
 
@@ -640,7 +665,7 @@ Node *CodeBlock_Node::make(Strategy strategy) {
   }
   CodeBlock_Node *o = new CodeBlock_Node();
   o->name("if (test())");
-  o->end_code_.clear();
+  if (o->end_code_) { free((void*)o->end_code_); o->end_code_ = 0; }
   o->add(anchor, strategy);
   o->factory = this;
   return o;
@@ -653,7 +678,7 @@ Node *CodeBlock_Node::make(Strategy strategy) {
  */
 void CodeBlock_Node::write_properties(fld::io::Project_Writer &f) {
   Node::write_properties(f);
-  if (!end_code().empty()) {
+  if (end_code()[0]) {
     f.write_string("after");
     f.write_word(end_code());
   }
@@ -691,8 +716,8 @@ void CodeBlock_Node::write_code1(fld::io::Code_Writer& f) {
  */
 void CodeBlock_Node::write_code2(fld::io::Code_Writer& f) {
   f.indentation--;
-  if (!end_code().empty())
-    f.write_c("%s} %s\n", f.indent(), end_code().c_str());
+  if (end_code()[0])
+    f.write_c("%s} %s\n", f.indent(), end_code());
   else
     f.write_c("%s}\n", f.indent());
 }
@@ -870,6 +895,15 @@ void Decl_Node::write_code1(fld::io::Code_Writer& f) {
  code. This can be used to store images inline in the source code,
  */
 
+Data_Node::Data_Node() {
+  filename_ = 0;
+  output_format_ = 0;
+}
+
+Data_Node::~Data_Node() {
+  if (filename_) free((void*)filename_);
+}
+
 /// Prototype for a data node to be used by the factory.
 Data_Node Data_Node::prototype;
 
@@ -890,7 +924,7 @@ Node *Data_Node::make(Strategy strategy) {
   Data_Node *o = new Data_Node();
   o->public_ = 1;
   o->static_ = 1;
-  o->filename_.clear();
+  if (o->filename_) { free((void*)o->filename_); o->filename_ = 0; }
   o->output_format_ = 0;
   o->name("myInlineData");
   o->add(anchor, strategy);
@@ -905,7 +939,7 @@ Node *Data_Node::make(Strategy strategy) {
  */
 void Data_Node::write_properties(fld::io::Project_Writer &f) {
   Decl_Node::write_properties(f);
-  if (!filename().empty()) {
+  if (filename()[0]) {
     f.write_string("filename");
     f.write_word(filename());
   }
@@ -953,14 +987,14 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
   const char *message = 0;
   const char *c = name();
   if (!c) return;
-  std::string fn = filename();
+  const char *fn = filename();
   char *data = 0;
   int nData = -1;
   int uncompressedDataSize = 0;
   // path should be set correctly already
-  if (!filename().empty() && !f.write_codeview) {
+  if (fn && fn[0] && !f.write_codeview) {
     Fluid.proj.enter_project_dir();
-    FILE *f = fl_fopen(filename().c_str(), "rb");
+    FILE *f = fl_fopen(fn, "rb");
     Fluid.proj.leave_project_dir();
     if (!f) {
       message = "Can't include data from file. Can't open";
@@ -984,7 +1018,7 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
       fclose(f);
     }
   } else {
-    if (filename().empty())
+    if (!fn || !fn[0])
       fn = "<no filename>";
   }
   if (is_in_class()) {
@@ -994,13 +1028,13 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
       write_comment_c(f);
       if (output_format_ == 1) {
         f.write_h("%sstatic const char *%s;\n", f.indent(1), c);
-        f.write_c("const char *%s::%s = /* text inlined from %s */\n", class_name(1), c, fn.c_str());
+        f.write_c("const char *%s::%s = /* text inlined from %s */\n", class_name(1), c, fn);
       } else {
         f.write_h_once("#include <string>");
         f.write_h("%sstatic const std::string %s;\n", f.indent(1), c);
-        f.write_c("const std::string %s::%s = /* text inlined from %s */\n", class_name(1), c, fn.c_str());
+        f.write_c("const std::string %s::%s = /* text inlined from %s */\n", class_name(1), c, fn);
       }
-      if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+      if (message) f.write_c("#error %s %s\n", message, fn);
       f.write_cstring(data, nData);
     } else if ((output_format_ == 2) || (output_format_ == 5)) {
       f.write_h("%sstatic int %s_size;\n", f.indent(1), c);
@@ -1009,28 +1043,28 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
       f.write_c("int %s::%s_size = %d;\n", class_name(1), c, uncompressedDataSize);
       if (output_format_ == 2) {
         f.write_h("%sstatic unsigned char %s[%d];\n", f.indent(1), c, nData);
-        f.write_c("unsigned char %s::%s[%d] = /* data compressed and inlined from %s */\n", class_name(1), c, nData, fn.c_str());
+        f.write_c("unsigned char %s::%s[%d] = /* data compressed and inlined from %s */\n", class_name(1), c, nData, fn);
       } else {
         f.write_h_once("#include <stdint.h>");
         f.write_h_once("#include <vector>");
         f.write_h("%sstatic std::vector<uint8_t> %s;\n", f.indent(1), c);
-        f.write_c("std::vector<uint8_t> %s::%s = /* data compressed and inlined from %s */\n", class_name(1), c, fn.c_str());
+        f.write_c("std::vector<uint8_t> %s::%s = /* data compressed and inlined from %s */\n", class_name(1), c, fn);
       }
-      if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+      if (message) f.write_c("#error %s %s\n", message, fn);
       f.write_cdata(data, nData);
     } else {
       f.write_c("\n");
       write_comment_c(f);
       if (output_format_ == 0) {
         f.write_h("%sstatic unsigned char %s[%d];\n", f.indent(1), c, nData);
-        f.write_c("unsigned char %s::%s[%d] = /* data inlined from %s */\n", class_name(1), c, nData, fn.c_str());
+        f.write_c("unsigned char %s::%s[%d] = /* data inlined from %s */\n", class_name(1), c, nData, fn);
       } else {
         f.write_h_once("#include <stdint.h>");
         f.write_h_once("#include <vector>");
         f.write_h("%sstatic std::vector<uint8_t> %s;\n", f.indent(1), c);
-        f.write_c("std::vector<uint8_t> %s::%s = /* data inlined from %s */\n", class_name(1), c, fn.c_str());
+        f.write_c("std::vector<uint8_t> %s::%s = /* data inlined from %s */\n", class_name(1), c, fn);
       }
-      if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+      if (message) f.write_c("#error %s %s\n", message, fn);
       f.write_cdata(data, nData);
     }
     f.write_c(";\n");
@@ -1043,13 +1077,13 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
           write_comment_c(f);
           if (output_format_ == 1) {
             f.write_h("extern const char *%s;\n", c);
-            f.write_c("const char *%s = /* text inlined from %s */\n", c, fn.c_str());
+            f.write_c("const char *%s = /* text inlined from %s */\n", c, fn);
           } else {
             f.write_h_once("#include <string>");
             f.write_h("extern const std::string %s;\n", c);
-            f.write_c("const std::string %s = /* text inlined from %s */\n", c, fn.c_str());
+            f.write_c("const std::string %s = /* text inlined from %s */\n", c, fn);
           }
-          if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+          if (message) f.write_c("#error %s %s\n", message, fn);
           f.write_cstring(data, nData);
         } else if ((output_format_ == 2) || (output_format_ == 5)) {
           f.write_h("extern int %s_size;\n", c);
@@ -1058,34 +1092,34 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
           f.write_c("int %s_size = %d;\n", c, uncompressedDataSize);
           if (output_format_ == 2) {
             f.write_h("extern unsigned char %s[%d];\n", c, nData);
-            f.write_c("unsigned char %s[%d] = /* data compressed and inlined from %s */\n", c, nData, fn.c_str());
+            f.write_c("unsigned char %s[%d] = /* data compressed and inlined from %s */\n", c, nData, fn);
           } else {
             f.write_h_once("#include <stdint.h>");
             f.write_h_once("#include <vector>");
             f.write_h("extern std::vector<uint8_t> %s;\n", c);
-            f.write_c("std::vector<uint8_t> %s = /* data compressed and inlined from %s */\n", c, fn.c_str());
+            f.write_c("std::vector<uint8_t> %s = /* data compressed and inlined from %s */\n", c, fn);
           }
-          if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+          if (message) f.write_c("#error %s %s\n", message, fn);
           f.write_cdata(data, nData);
         } else {
           f.write_c("\n");
           write_comment_c(f);
           if (output_format_ == 0) {
             f.write_h("extern unsigned char %s[%d];\n", c, nData);
-            f.write_c("unsigned char %s[%d] = /* data inlined from %s */\n", c, nData, fn.c_str());
+            f.write_c("unsigned char %s[%d] = /* data inlined from %s */\n", c, nData, fn);
           } else {
             f.write_h_once("#include <stdint.h>");
             f.write_h_once("#include <vector>");
             f.write_h("extern std::vector<uint8_t> %s;\n", c);
-            f.write_c("std::vector<uint8_t> %s = /* data inlined from %s */\n", c, fn.c_str());
+            f.write_c("std::vector<uint8_t> %s = /* data inlined from %s */\n", c, fn);
           }
-          if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+          if (message) f.write_c("#error %s %s\n", message, fn);
           f.write_cdata(data, nData);
         }
         f.write_c(";\n");
       } else {
         write_comment_h(f);
-        f.write_h("#error Unsupported declaration loading inline data %s\n", fn.c_str());
+        f.write_h("#error Unsupported declaration loading inline data %s\n", fn);
         if (output_format_ == 1)
           f.write_h("const char *%s = \"abc...\";\n", c);
         else
@@ -1097,39 +1131,39 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
       if ((output_format_ == 1) || (output_format_ == 4)) {
         if (output_format_ == 1) {
           if (static_) f.write_c("static ");
-          f.write_c("const char *%s = /* text inlined from %s */\n", c, fn.c_str());
+          f.write_c("const char *%s = /* text inlined from %s */\n", c, fn);
         } else {
           f.write_c_once("#include <string>");
           if (static_) f.write_c("static ");
-          f.write_c("const std::string %s = /* text inlined from %s */\n", c, fn.c_str());
+          f.write_c("const std::string %s = /* text inlined from %s */\n", c, fn);
         }
-        if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+        if (message) f.write_c("#error %s %s\n", message, fn);
         f.write_cstring(data, nData);
       } else if ((output_format_ == 2) || (output_format_ == 5)) {
         if (static_) f.write_c("static ");
         f.write_c("int %s_size = %d;\n", c, uncompressedDataSize);
         if (output_format_ == 2) {
           if (static_) f.write_c("static ");
-          f.write_c("unsigned char %s[%d] = /* data compressed and inlined from %s */\n", c, nData, fn.c_str());
+          f.write_c("unsigned char %s[%d] = /* data compressed and inlined from %s */\n", c, nData, fn);
         } else {
           f.write_c_once("#include <stdint.h>");
           f.write_c_once("#include <vector>");
           if (static_) f.write_c("static ");
-          f.write_c("std::vector<uint8_t> %s = /* data compressed and inlined from %s */\n", c, fn.c_str());
+          f.write_c("std::vector<uint8_t> %s = /* data compressed and inlined from %s */\n", c, fn);
         }
-        if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+        if (message) f.write_c("#error %s %s\n", message, fn);
         f.write_cdata(data, nData);
       } else {
         if (output_format_ == 0) {
           if (static_) f.write_c("static ");
-          f.write_c("unsigned char %s[%d] = /* data inlined from %s */\n", c, nData, fn.c_str());
+          f.write_c("unsigned char %s[%d] = /* data inlined from %s */\n", c, nData, fn);
         } else {
           f.write_c_once("#include <stdint.h>");
           f.write_c_once("#include <vector>");
           if (static_) f.write_c("static ");
-          f.write_c("std::vector<uint8_t> %s = /* data inlined from %s */\n", c, fn.c_str());
+          f.write_c("std::vector<uint8_t> %s = /* data inlined from %s */\n", c, fn);
         }
-        if (message) f.write_c("#error %s %s\n", message, fn.c_str());
+        if (message) f.write_c("#error %s %s\n", message, fn);
         f.write_cdata(data, nData);
       }
       f.write_c(";\n");
@@ -1139,9 +1173,9 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
   // giving the error: (Fluid.batch_mode && !write_codeview) ???
   if (message && !f.write_codeview) {
     if (Fluid.batch_mode)
-      fprintf(stderr, "FLUID ERROR: %s %s\n", message, fn.c_str());
+      fprintf(stderr, "FLUID ERROR: %s %s\n", message, fn);
     else
-      fl_alert("%s\n%s\n", message, fn.c_str());
+      fl_alert("%s\n%s\n", message, fn);
   }
   if (data) free(data);
 }
@@ -1157,6 +1191,15 @@ void Data_Node::write_code1(fld::io::Code_Writer& f) {
  is written to the source file, and to the header file, if declared public.
  */
 
+DeclBlock_Node::DeclBlock_Node() {
+  end_code_ = 0;
+  write_map_ = CODE_IN_SOURCE;
+}
+
+DeclBlock_Node::~DeclBlock_Node() {
+  if (end_code_) free((void*)end_code_);
+}
+
 /// Prototype for a declaration block to be used by the factory.
 DeclBlock_Node DeclBlock_Node::prototype;
 
@@ -1247,11 +1290,11 @@ void DeclBlock_Node::write_static(fld::io::Code_Writer& f) {
  Write the \b after static code to the source file, and to the header file if declared public.
  */
 void DeclBlock_Node::write_static_after(fld::io::Code_Writer& f) {
-  if (!end_code().empty()) {
+  if (end_code()[0]) {
     if (write_map_ & STATIC_IN_HEADER)
-      f.write_h("%s\n", end_code().c_str());
+      f.write_h("%s\n", end_code());
     if (write_map_ & STATIC_IN_SOURCE)
-      f.write_c("%s\n", end_code().c_str());
+      f.write_c("%s\n", end_code());
   }
 }
 
@@ -1273,11 +1316,11 @@ void DeclBlock_Node::write_code1(fld::io::Code_Writer& f) {
  Write the \b after code to the source file, and to the header file if declared public.
  */
 void DeclBlock_Node::write_code2(fld::io::Code_Writer& f) {
-  if (!end_code().empty()) {
+  if (end_code()[0]) {
     if (write_map_ & CODE_IN_HEADER)
-      f.write_h("%s\n", end_code().c_str());
+      f.write_h("%s\n", end_code());
     if (write_map_ & CODE_IN_SOURCE)
-      f.write_c("%s\n", end_code().c_str());
+      f.write_c("%s\n", end_code());
   }
 }
 
@@ -1424,6 +1467,17 @@ void Comment_Node::write_code1(fld::io::Code_Writer& f) {
  Manage a class declaration and implementation.
  */
 
+Class_Node::Class_Node() {
+  base_class_ = 0;
+  prefix_ = 0;
+  public_ = 1;
+}
+
+Class_Node::~Class_Node() {
+  if (base_class_) free((void*)base_class_);
+  if (prefix_) free((void*)prefix_);
+}
+
 /// Prototype for a class node to be used by the factory.
 Class_Node Class_Node::prototype;
 
@@ -1465,7 +1519,7 @@ Node *Class_Node::make(Strategy strategy) {
  */
 void Class_Node::write_properties(fld::io::Project_Writer &f) {
   Node::write_properties(f);
-  if (!base_class().empty()) {
+  if (base_class()[0]) {
     f.write_string(":");
     f.write_word(base_class());
   }
@@ -1506,12 +1560,12 @@ void Class_Node::write_code1(fld::io::Code_Writer& f) {
   write_public_state = 0;
   f.write_h("\n");
   write_comment_h(f);
-  if (!prefix().empty())
-    f.write_h("class %s %s ", prefix().c_str(), name());
+  if (prefix()[0])
+    f.write_h("class %s %s ", prefix(), name());
   else
     f.write_h("class %s ", name());
-  if (!base_class().empty()) {
-    f.write_h(": %s ", base_class().c_str());
+  if (base_class()[0]) {
+    f.write_h(": %s ", base_class());
   }
   f.write_h("{\n");
 }
diff --git a/fluid/nodes/Function_Node.h b/fluid/nodes/Function_Node.h
index 0ad4494f3..87664e317 100644
--- a/fluid/nodes/Function_Node.h
+++ b/fluid/nodes/Function_Node.h
@@ -34,8 +34,6 @@
 #include <stdarg.h>
 #include <stdlib.h>
 
-#include <string>
-
 extern class Class_Node *current_class;
 
 int has_toplevel_function(const char *rtype, const char *sig);
@@ -51,15 +49,15 @@ public:
   static Function_Node prototype;
 
 private:
-  std::string return_type_;
-  char public_ = 0;
-  char declare_c_ = 0;
-  char constructor = 0;
-  char havewidgets = 0;
+  const char *return_type_;
+  char public_;
+  char declare_c_;
+  char constructor;
+  char havewidgets;
 
 public:
-  Function_Node() = default;
-  ~Function_Node() override = default;
+  Function_Node();
+  ~Function_Node();
 
   Node *make(Strategy strategy) override;
   void write_code1(fld::io::Code_Writer& f) override;
@@ -76,8 +74,8 @@ public:
   void write_properties(fld::io::Project_Writer &f) override;
   void read_property(fld::io::Project_Reader &f, const char *) override;
   int has_signature(const char *, const char*) const;
-  std::string return_type() const { return return_type_; }
-  void return_type(const std::string& t) { storestring(t, return_type_); }
+  const char *return_type() const { return return_type_ ? return_type_ : ""; }
+  void return_type(const char *t) { storestring(t, return_type_); }
   char visibility() { return public_; }
   void visibility(char v) { public_ = v; }
   char declare_c() { return declare_c_; }
@@ -132,11 +130,11 @@ public:
   static CodeBlock_Node prototype;
   
 private:
-  std::string end_code_;
+  const char *end_code_;
 
 public:
-  CodeBlock_Node() = default;
-  ~CodeBlock_Node() override = default;
+  CodeBlock_Node();
+  ~CodeBlock_Node();
 
   Node *make(Strategy strategy) override;
   void write_code1(fld::io::Code_Writer& f) override;
@@ -150,8 +148,8 @@ public:
   bool is_a(Type inType) const override { return (inType==FLD_NODE_TYPE_CodeBlock) ? true : super::is_a(inType); }
   void write_properties(fld::io::Project_Writer &f) override;
   void read_property(fld::io::Project_Reader &f, const char *) override;
-  std::string end_code() const { return end_code_; }
-  void end_code(const std::string& c) { storestring(c, end_code_); }
+  const char *end_code() const { return end_code_ ? end_code_ : ""; }
+  void end_code(const char *c) { storestring(c, end_code_); }
 };
 
 // ---- Decl_Node declaration
@@ -195,12 +193,12 @@ public:
   static Data_Node prototype;
 
 private:
-  std::string filename_;
-  int output_format_ = 0;
+  const char *filename_;
+  int output_format_;
 
 public:
-  Data_Node() = default;
-  ~Data_Node() override = default;
+  Data_Node();
+  ~Data_Node();
 
   Node *make(Strategy strategy) override;
   void write_code1(fld::io::Code_Writer& f) override;
@@ -211,8 +209,8 @@ public:
   void read_property(fld::io::Project_Reader &f, const char *) override;
   Type type() const override { return FLD_NODE_TYPE_Data; }
   bool is_a(Type inType) const override { return (inType==FLD_NODE_TYPE_Data) ? true : super::is_a(inType); }
-  void filename(const std::string& fn) { storestring(fn, filename_); }
-  std::string filename() const { return filename_; }
+  void filename(const char *fn) { storestring(fn, filename_); }
+  const char *filename() const { return filename_ ? filename_ : ""; }
   int output_format() { return output_format_; }
   void output_format(int fmt) { output_format_ = fmt; }
 };
@@ -232,12 +230,12 @@ public:
   };
 
 private:
-  std::string end_code_;            ///< code after all children of this block
-  int write_map_ = CODE_IN_SOURCE;  ///< see enum above
+  const char *end_code_;            ///< code after all children of this block
+  int write_map_;                   ///< see enum above
 
 public:
-  DeclBlock_Node() = default;
-  ~DeclBlock_Node() override = default;
+  DeclBlock_Node();
+  ~DeclBlock_Node();
 
   Node *make(Strategy strategy) override;
   void write_static(fld::io::Code_Writer& f) override;
@@ -253,8 +251,8 @@ public:
   int is_public() const override;
   Type type() const override { return FLD_NODE_TYPE_DeclBlock; }
   bool is_a(Type inType) const override { return (inType==FLD_NODE_TYPE_DeclBlock) ? true : super::is_a(inType); }
-  std::string end_code() const { return end_code_; }
-  void end_code(const std::string& p) { storestring(p, end_code_); }
+  const char *end_code() const { return end_code_ ? end_code_ : ""; }
+  void end_code(const char *p) { storestring(p, end_code_); }
   int write_map() { return write_map_; }
   void write_map(int v) { write_map_ = v; }
 };
@@ -301,13 +299,13 @@ public:
   static Class_Node prototype;
 
 private:
-  std::string base_class_;
-  std::string prefix_;
-  char public_ = 1;
+  const char *base_class_;
+  const char *prefix_;
+  char public_;
 
 public:
-  Class_Node() = default;
-  ~Class_Node() override = default;
+  Class_Node();
+  ~Class_Node();
 
   // State variables used when writing code to file
   char write_public_state; // true when public: has been printed
@@ -328,17 +326,17 @@ public:
   void read_property(fld::io::Project_Reader &f, const char *) override;
 
   /** Get base class access and name. */
-  std::string base_class() const { return base_class_; }
+  const char *base_class() const { return base_class_ ? base_class_ : ""; }
   /** Set base class access and name, i.e. `public Fl_Widget`. */
-  void base_class(const std::string& name) { storestring(name, base_class_); }
+  void base_class(const char *name) { storestring(name, base_class_); }
 
   char visibility() { return public_; }
   void visibility(char v) { public_ = v; }
 
   /** Get the text between `class` and the class name */
-  std::string prefix() const { return prefix_; }
+  const char *prefix() const { return prefix_ ? prefix_ : ""; }
   /** Set the text between `class` and the class name */
-  void prefix(const std::string& p) { prefix_ = p; }
+  void prefix(const char *p) { storestring(p, prefix_); }
 };
 
 #endif // FLUID_NODES_FUNCTION_NODE_H
diff --git a/fluid/nodes/Node.cxx b/fluid/nodes/Node.cxx
index 2971bad2d..8e0041f3c 100644
--- a/fluid/nodes/Node.cxx
+++ b/fluid/nodes/Node.cxx
@@ -455,18 +455,6 @@ int storestring(const char *n, const char * & p, int nostrip) {
   return 1;
 }
 
-// C++11 version, still using the original to copy all the side effects.
-int storestring(const std::string& n, std::string& p, int nostrip) {
-  const char *buffer { 0 };
-  int ret = storestring(n.c_str(), buffer);
-  if (buffer) {
-    p = buffer;
-    free((void*)buffer);
-  } else {
-    p.clear();
-  }
-  return ret;
-}
 
 /** Update the `visible` flag for `p` and all its descendants.
  \param[in] p start here and update all descendants
@@ -902,8 +890,8 @@ void Node::write(fld::io::Project_Writer &f) {
   f.write_word(type_name());
 
   if (is_class()) {
-    auto p = ((Class_Node*)this)->prefix();
-    if (!p.empty())
+    const char *p = ((Class_Node*)this)->prefix();
+    if (p[0])
       f.write_word(p);
   }
 
diff --git a/fluid/nodes/Node.h b/fluid/nodes/Node.h
index 02338903f..a20dd7258 100644
--- a/fluid/nodes/Node.h
+++ b/fluid/nodes/Node.h
@@ -22,8 +22,6 @@
 #include <FL/Fl_Widget.H>
 #include <FL/fl_draw.H>
 
-#include <string>
-
 class Node;
 class Group_Node;
 class Window_Node;
@@ -117,7 +115,6 @@ typedef NodeType Type;
 void update_visibility_flag(Node *p);
 void delete_all(int selected_only=0);
 int storestring(const char *n, const char * & p, int nostrip=0);
-int storestring(const std::string& n, std::string& p, int nostrip=0);
 
 void select_all_cb(Fl_Widget *,void *);
 void select_none_cb(Fl_Widget *,void *);
diff --git a/fluid/nodes/Tree.cxx b/fluid/nodes/Tree.cxx
index a163c4181..d437b5bd3 100644
--- a/fluid/nodes/Tree.cxx
+++ b/fluid/nodes/Tree.cxx
@@ -92,7 +92,7 @@ Tree::Tree(Project &proj)
  \return the node with this uid, or 0 if not found
  */
 Node *Tree::find_by_uid(unsigned short uid) {
-  for (auto tp: all_nodes()) {
+  for (Node *tp: all_nodes()) {
     if (tp->get_uid() == uid) return tp;
   }
   return 0;
@@ -106,7 +106,7 @@ Node *Tree::find_by_uid(unsigned short uid) {
  \return the node we found or 0
  */
 Node *Tree::find_in_text(int text_type, int crsr) {
-  for (auto node: all_nodes()) {
+  for (Node *node: all_nodes()) {
     switch (text_type) {
       case 0:
         if (crsr >= node->code1_start && crsr < node->code1_end) return node;
diff --git a/fluid/nodes/Window_Node.cxx b/fluid/nodes/Window_Node.cxx
index 0c3b0f01c..2bcd9f1b1 100644
--- a/fluid/nodes/Window_Node.cxx
+++ b/fluid/nodes/Window_Node.cxx
@@ -1386,13 +1386,13 @@ void Widget_Class_Node::write_code1(fld::io::Code_Writer& f) {
   current_widget_class = this;
   write_public_state = 1;
 
-  std::string c = subclass();
-  if (c.empty()) c = "Fl_Group";
+  const char *c = subclass();
+  if (!c || !c[0]) c = "Fl_Group";
 
   f.write_c("\n");
   write_comment_h(f);
-  f.write_h("\nclass %s : public %s {\n", name(), c.c_str());
-  if (c.find("Window")!=c.npos) {
+  f.write_h("\nclass %s : public %s {\n", name(), c);
+  if (strstr(c, "Window") != 0) {
     f.write_h("%svoid _%s();\n", f.indent(1), trimclassname(name()));
     f.write_h("public:\n");
     f.write_h("%s%s(int X, int Y, int W, int H, const char *L = 0);\n", f.indent(1), trimclassname(name()));
@@ -1401,20 +1401,20 @@ void Widget_Class_Node::write_code1(fld::io::Code_Writer& f) {
 
     // a constructor with all four dimensions plus label
     f.write_c("%s::%s(int X, int Y, int W, int H, const char *L) :\n", name(), trimclassname(name()));
-    f.write_c("%s%s(X, Y, W, H, L)\n{\n", f.indent(1), c.c_str());
+    f.write_c("%s%s(X, Y, W, H, L)\n{\n", f.indent(1), c);
     f.write_c("%s_%s();\n", f.indent(1), trimclassname(name()));
     f.write_c("}\n\n");
 
     // a constructor with just the size and label. The window manager will position the window
     f.write_c("%s::%s(int W, int H, const char *L) :\n", name(), trimclassname(name()));
-    f.write_c("%s%s(0, 0, W, H, L)\n{\n", f.indent(1), c.c_str());
+    f.write_c("%s%s(0, 0, W, H, L)\n{\n", f.indent(1), c);
     f.write_c("%sclear_flag(16);\n", f.indent(1));
     f.write_c("%s_%s();\n", f.indent(1), trimclassname(name()));
     f.write_c("}\n\n");
 
     // a constructor that takes size and label from the Fluid database
     f.write_c("%s::%s() :\n", name(), trimclassname(name()));
-    f.write_c("%s%s(0, 0, %d, %d, ", f.indent(1), c.c_str(), o->w(), o->h());
+    f.write_c("%s%s(0, 0, %d, %d, ", f.indent(1), c, o->w(), o->h());
     const char *cstr = label();
     if (cstr) f.write_cstring(cstr);
     else f.write_c("0");
@@ -1431,11 +1431,11 @@ void Widget_Class_Node::write_code1(fld::io::Code_Writer& f) {
             f.indent(1), trimclassname(name()));
     f.write_c("%s::%s(int X, int Y, int W, int H, const char *L) :\n", name(), trimclassname(name()));
     if (wc_relative==1)
-      f.write_c("%s%s(0, 0, W, H, L)\n{\n", f.indent(1), c.c_str());
+      f.write_c("%s%s(0, 0, W, H, L)\n{\n", f.indent(1), c);
     else if (wc_relative==2)
-      f.write_c("%s%s(0, 0, %d, %d, L)\n{\n", f.indent(1), c.c_str(), o->w(), o->h());
+      f.write_c("%s%s(0, 0, %d, %d, L)\n{\n", f.indent(1), c, o->w(), o->h());
     else
-      f.write_c("%s%s(X, Y, W, H, L)\n{\n", f.indent(1), c.c_str());
+      f.write_c("%s%s(X, Y, W, H, L)\n{\n", f.indent(1), c);
   }
 
 //  f.write_c("%s%s *o = this;\n", f.indent(1), name());
diff --git a/fluid/nodes/factory.cxx b/fluid/nodes/factory.cxx
index 792a9ff72..70e960edd 100644
--- a/fluid/nodes/factory.cxx
+++ b/fluid/nodes/factory.cxx
@@ -390,7 +390,7 @@ private:
   }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->textsize_not_null() + 8;
     w = layout->textsize_not_null() * 4 + 4 * h; // make room for the arrows
     fld::app::Snap_Action::better_size(w, h);
@@ -420,7 +420,7 @@ public:
   static Adjuster_Node prototype;
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->labelsize + 8;
     w = 3 * h;
     fld::app::Snap_Action::better_size(w, h);
@@ -495,7 +495,7 @@ private:
   Fl_Menu_Item *subtypes() override { return roller_type_menu; }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     w = layout->labelsize + 8;
     h = 4 * w;
     fld::app::Snap_Action::better_size(w, h);
@@ -539,7 +539,7 @@ private:
   Fl_Menu_Item *subtypes() override { return slider_type_menu; }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     w = layout->labelsize + 8;
     h = 4 * w;
     fld::app::Snap_Action::better_size(w, h);
@@ -649,7 +649,7 @@ private:
   }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->textsize_not_null() + 8;
     w = layout->textsize_not_null() * 4 + 8;
     fld::app::Snap_Action::better_size(w, h);
@@ -692,7 +692,7 @@ private:
   }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->textsize_not_null() + 8;
     w = layout->textsize_not_null() * 4 + 8;
     fld::app::Snap_Action::better_size(w, h);
@@ -751,7 +751,7 @@ private:
   }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->textsize_not_null() + 8;
     w = layout->textsize_not_null() * 6 + 8;
     fld::app::Snap_Action::better_size(w, h);
@@ -793,7 +793,7 @@ private:
   Fl_Menu_Item *subtypes() override { return 0; } // Don't inherit.
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->textsize_not_null() + 8 + 10; // Directoy bar is additional 10 pixels high
     w = layout->textsize_not_null() * 10 + 8;
     fld::app::Snap_Action::better_size(w, h);
@@ -877,7 +877,7 @@ private:
   }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->textsize_not_null() * 4 + 8;
     w = layout->textsize_not_null() * 10 + 8;
     fld::app::Snap_Action::better_size(w, h);
@@ -1101,7 +1101,7 @@ public:
   static Progress_Node prototype;
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->labelsize + 8;
     w = layout->labelsize * 12;
     fld::app::Snap_Action::better_size(w, h);
@@ -1153,7 +1153,7 @@ private:
   }
 public:
   void ideal_size(int &w, int &h) override {
-    auto layout = Fluid.proj.layout;
+    fld::app::Layout_Preset *layout = Fluid.proj.layout;
     h = layout->textsize_not_null() + 8;
     w = layout->textsize_not_null() * 4 + 8;
     fld::app::Snap_Action::better_size(w, h);
@@ -1282,11 +1282,11 @@ static Node *known_types[] = {
 Node *add_new_widget_from_user(Node *inPrototype, Strategy strategy, bool and_open) {
   Fluid.proj.undo.checkpoint();
   Fluid.proj.undo.suspend();
-  auto layout = Fluid.proj.layout;
+  fld::app::Layout_Preset *layout = Fluid.proj.layout;
   Node *t = ((Node*)inPrototype)->make(strategy);
   if (t) {
     if (t->is_widget() && !t->is_a(FLD_NODE_TYPE_Window)) {
-      auto layout = Fluid.proj.layout;
+      fld::app::Layout_Preset *layout = Fluid.proj.layout;
       Widget_Node *wt = (Widget_Node *)t;
       bool changed = false;
 
diff --git a/fluid/panels/widget_panel.cxx b/fluid/panels/widget_panel.cxx
index 897cec6cc..1f60bc178 100644
--- a/fluid/panels/widget_panel.cxx
+++ b/fluid/panels/widget_panel.cxx
@@ -32,7 +32,7 @@
 #include <FL/Fl_File_Chooser.H>
 #include <ctype.h>
 #include <stdlib.h>    // free()
-#include <functional>    // std::function
+#include <string.h>
 #define ZERO_ENTRY 1000
 extern const char* when_symbol_name(int n);
 extern void set_whenmenu(int n);
@@ -57,37 +57,6 @@ static int use_tab_navigation(int, Fl_Text_Editor*) {
 //fl ▲ ----------~~-~=---~-------------~-=--~~-=~=-~~--~-~=-- ▲ fl//
 }
 
-static void update_current(Fl_Input* o, void *v,
-  std::function<std::string()> getter,
-  std::function<void(std::string)> setter) {
-//fl ▼ ------------------------ code --~---=~--=-=-=---~=~~=~ ▼ fl//
-  if (v == LOAD) {
-    o->value( getter().c_str() );
-  } else {
-    std::string v = o->value();
-    if (v != getter()) {
-      setter(v);
-      Fluid.proj.set_modflag(1);
-    }
-  }
-//fl ▲ ----------~~~=~---=~-------------~=-~--~=~~-=--=-==~-= ▲ fl//
-}
-
-static void update_current(Fl_Text_Editor* o, void *v,
-  std::function<std::string()> getter,
-  std::function<void(std::string)> setter) {
-//fl ▼ ------------------------ code ----~-~-=~~~~=-~-==--~-- ▼ fl//
-  if (v == LOAD) {
-    o->buffer()->text( getter().c_str() );
-  } else {
-    std::string v = o->buffer()->text();
-    if (v != getter()) {
-      setter(v);
-      Fluid.proj.set_modflag(1);
-    }
-  }
-//fl ▲ ----------~~-=-~=--=-=----------~-~~=-~-~~-~~==~~--=~- ▲ fl//
-}
 
 Fl_Double_Window *image_panel_window=(Fl_Double_Window *)0;
 
@@ -2619,10 +2588,15 @@ static void cb_wp_data_filename(Fl_Input* o, void* v) {
 //fl ▼ ---------------------- callback ~-~=~~~~~~-=~~=~-==--- ▼ fl//
   if (!current_node || !current_node->is_a(FLD_NODE_TYPE_Data)) return;
   Data_Node* nd = (Data_Node*)current_node;
-  update_current(o, v,
-    [nd](){return nd->filename();},
-    [nd](std::string s){nd->filename(s);}
-  );
+  if (v == LOAD) {
+    o->value(nd->filename());
+  } else {
+    const char *val = o->value();
+    if (strcmp(val ? val : "", nd->filename()) != 0) {
+      nd->filename(val);
+      Fluid.proj.set_modflag(1);
+    }
+  }
 //fl ▲ ----------~=-~--=--~------------~-~==--==-~=---==--~-~ ▲ fl//
 }
 
@@ -2885,12 +2859,13 @@ static void cb_Attribute(Fl_Input* o, void* v) {
   Class_Node* nd = (Class_Node*)current_node;
 
   if (v == LOAD) {
-    o->value( nd->prefix().c_str() );
+    o->value( nd->prefix() );
   } else {
-    auto nn = nd->prefix();
-    if (nn != o->value())
+    const char *nn = nd->prefix();
+    const char *ov = o->value();
+    if (strcmp(nn ? nn : "", ov ? ov : "") != 0)
     {
-      nd->prefix( o->value() );
+      nd->prefix( ov );
       Fluid.proj.set_modflag(1);
     }
   }
@@ -2948,11 +2923,12 @@ static void cb_Base(Fl_Input* o, void* v) {
   Class_Node* nd = (Class_Node*)current_node;
 
   if (v == LOAD) {
-    o->value( nd->base_class().c_str() );
+    o->value( nd->base_class() );
   } else {
-    auto nn = nd->base_class();
-    if (nn != o->value()) {
-      nd->base_class( o->value() );
+    const char *nn = nd->base_class();
+    const char *ov = o->value();
+    if (strcmp(nn ? nn : "", ov ? ov : "") != 0) {
+      nd->base_class( ov );
       Fluid.proj.set_modflag(1);
     }
   }
@@ -3018,10 +2994,15 @@ static void cb_End(Fl_Input* o, void* v) {
 //fl ▼ ---------------------- callback -~-~--~-----=-~~~~~=-~ ▼ fl//
   if (!current_node || !current_node->is_a(FLD_NODE_TYPE_DeclBlock)) return;
   DeclBlock_Node* nd = (DeclBlock_Node*)current_node;
-  update_current(o, v,
-    [nd](){return nd->end_code();},
-    [nd](std::string s){nd->end_code(s);}
-  );
+  if (v == LOAD) {
+    o->value(nd->end_code());
+  } else {
+    const char *val = o->value();
+    if (strcmp(val ? val : "", nd->end_code()) != 0) {
+      nd->end_code(val);
+      Fluid.proj.set_modflag(1);
+    }
+  }
 //fl ▲ ----------=~~~~~~=~-=-------------=~--~=~--=~~~=~~-~~= ▲ fl//
 }
 
@@ -3295,10 +3276,15 @@ static void cb_End1(Fl_Input* o, void* v) {
 //fl ▼ ---------------------- callback ~~-~~=~=-~=-~-=~~~=-=~ ▼ fl//
   if (!current_node || !current_node->is_a(FLD_NODE_TYPE_CodeBlock)) return;
   CodeBlock_Node* nd = (CodeBlock_Node*)current_node;
-  update_current(o, v,
-    [nd](){return nd->end_code();},
-    [nd](std::string s){nd->end_code(s);}
-  );
+  if (v == LOAD) {
+    o->value(nd->end_code());
+  } else {
+    const char *val = o->value();
+    if (strcmp(val ? val : "", nd->end_code()) != 0) {
+      nd->end_code(val);
+      Fluid.proj.set_modflag(1);
+    }
+  }
 //fl ▲ ----------~=----=-~-=~----------~~~~-~-=~--=-=~~=---~~ ▲ fl//
 }
 
@@ -3487,10 +3473,15 @@ static void cb_Return(fld::widget::Code_Editor* o, void* v) {
 //fl ▼ ---------------------- callback -~=--~-~=~=~~~---=~~=~ ▼ fl//
   if (!current_node || !current_node->is_a(FLD_NODE_TYPE_Function)) return;
   Function_Node* nd = (Function_Node*)current_node;
-  update_current(o, v,
-    [nd](){return nd->return_type();},
-    [nd](std::string s){nd->return_type(s);}
-  );
+  if (v == LOAD) {
+    o->buffer()->text(nd->return_type());
+  } else {
+    const char *val = o->buffer()->text();
+    if (strcmp(val ? val : "", nd->return_type()) != 0) {
+      nd->return_type(val);
+      Fluid.proj.set_modflag(1);
+    }
+  }
 //fl ▲ ----------~=~~=~~==~~-----------~~=~=-~=~-~-~-=~-=~--~ ▲ fl//
 }
 
diff --git a/fluid/proj/mergeback.cxx b/fluid/proj/mergeback.cxx
index d19893042..bb7ef5504 100644
--- a/fluid/proj/mergeback.cxx
+++ b/fluid/proj/mergeback.cxx
@@ -17,6 +17,7 @@
 #include "proj/mergeback.h"
 
 #include "Fluid.h"
+#include "Project.h"
 #include "proj/undo.h"
 #include "io/Code_Writer.h"
 #include "nodes/Function_Node.h"
@@ -28,6 +29,7 @@
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <ctype.h>
 #include <zlib.h>
 
@@ -35,9 +37,6 @@ extern void propagate_load(Fl_Group*, void*);
 extern void load_panel();
 extern void redraw_browser();
 
-using namespace fld;
-using namespace fld::proj;
-
 // TODO: add application user setting to control mergeback
 //        [] new projects default to mergeback
 //        [] check mergeback when loading project
@@ -101,7 +100,7 @@ using namespace fld::proj;
  \return -2 if no code file was found
  \return see above
  */
-int merge_back(Project &proj, const std::string &s, const std::string &p, Mergeback::Task task) {
+static int merge_back(fld::Project &proj, const char *s, const char *p, Mergeback::Task task) {
   if (proj.write_mergeback_data) {
     Mergeback mergeback(proj);
     return mergeback.merge_back(s, p, task);
@@ -112,7 +111,7 @@ int merge_back(Project &proj, const std::string &s, const std::string &p, Mergeb
 }
 
 /** Allocate and initialize MergeBack class. */
-Mergeback::Mergeback(Project &proj)
+Mergeback::Mergeback(fld::Project &proj)
 : proj_(proj),
   code(0),
   line_no(0),
@@ -153,9 +152,9 @@ void Mergeback::unindent(char *s) {
  Read a block of text from the source file and remove the leading two spaces in every line.
  \param[in] start start of the block within the file
  \param[in] end end of text within the file
- \return a string holding the text that was found in the file
+ \return a malloc'd string holding the text that was found in the file (caller must free)
  */
-std::string Mergeback::read_and_unindent_block(long start, long end) {
+char *Mergeback::read_and_unindent_block(long start, long end) {
   long bsize = end-start;
   long here = ::ftell(code);
   ::fseek(code, start, SEEK_SET);
@@ -166,10 +165,8 @@ std::string Mergeback::read_and_unindent_block(long start, long end) {
   else
     block[bsize] = 0;
   unindent(block);
-  std::string str = block;
-  ::free(block);
   ::fseek(code, here, SEEK_SET);
-  return str;
+  return block;
 }
 
 /** Tell user the results of our MergeBack analysis and pop up a dialog to give
@@ -179,12 +176,12 @@ std::string Mergeback::read_and_unindent_block(long start, long end) {
  \return -1 if the user wants to cancel or an error occurred or an issue was presented
         (message or choice dialog was shown)
  */
-int Mergeback::ask_user_to_merge(const std::string &code_filename, const std::string &proj_filename) {
+int Mergeback::ask_user_to_merge(const char *code_filename, const char *proj_filename) {
   if (tag_error) {
     fl_message("Comparing\n  \"%s\"\nto\n  \"%s\"\n\n"
                "MergeBack found an error in line %d while reading tags\n"
                "from the source code. Merging code back is not possible.",
-               code_filename.c_str(), proj_filename.c_str(), line_no);
+               code_filename, proj_filename, line_no);
     return -1;
   }
   if (!num_changed_code && !num_changed_structure) {
@@ -196,39 +193,47 @@ int Mergeback::ask_user_to_merge(const std::string &code_filename, const std::st
                "of the source code. These kind of changes can not be\n"
                "merged back and will be lost when the source code is\n"
                "generated again from the open project.",
-               code_filename.c_str(), proj_filename.c_str(), num_changed_structure);
+               code_filename, proj_filename, num_changed_structure);
     return -1;
   }
-  std::string msg = "Comparing\n  \"%1$s\"\nto\n  \"%2$s\"\n\n"
-                  "MergeBack found %3$d modifications in the source code.";
+  char msg[2048];
+  int pos = 0;
+  pos += snprintf(msg + pos, sizeof(msg) - pos,
+                  "Comparing\n  \"%%1$s\"\nto\n  \"%%2$s\"\n\n"
+                  "MergeBack found %%3$d modifications in the source code.");
   if (num_possible_override)
-    msg += "\n\nWARNING: %6$d of these modified blocks appear to also have\n"
-    "changed in the project. Merging will override changes in\n"
-    "the project with changes from the source code file.";
+    pos += snprintf(msg + pos, sizeof(msg) - pos,
+                    "\n\nWARNING: %%6$d of these modified blocks appear to also have\n"
+                    "changed in the project. Merging will override changes in\n"
+                    "the project with changes from the source code file.");
   if (num_uid_not_found)
-    msg += "\n\nWARNING: no Node can be found for %4$d of these\n"
-    "modifications and they can not be merged back.";
+    pos += snprintf(msg + pos, sizeof(msg) - pos,
+                    "\n\nWARNING: no Node can be found for %%4$d of these\n"
+                    "modifications and they can not be merged back.");
   if (!num_possible_override && !num_uid_not_found)
-    msg += "\nMerging these changes back appears to be safe.";
+    pos += snprintf(msg + pos, sizeof(msg) - pos,
+                    "\nMerging these changes back appears to be safe.");
 
   if (num_changed_structure)
-    msg += "\n\nWARNING: %5$d modifications were found in the project\n"
-    "structure. These kind of changes can not be merged back\n"
-    "and will be lost when the source code is generated again\n"
-    "from the open project.";
+    pos += snprintf(msg + pos, sizeof(msg) - pos,
+                    "\n\nWARNING: %%5$d modifications were found in the project\n"
+                    "structure. These kind of changes can not be merged back\n"
+                    "and will be lost when the source code is generated again\n"
+                    "from the open project.");
 
   if (num_changed_code==num_uid_not_found) {
-    fl_message(msg.c_str(),
-               code_filename.c_str(), proj_filename.c_str(),
+    fl_message(msg,
+               code_filename, proj_filename,
                num_changed_code, num_uid_not_found,
                num_changed_structure, num_possible_override);
     return -1;
   } else {
-    msg +=    "\n\nClick Cancel to abort the MergeBack operation.\n"
-    "Click Merge to merge all code changes back into\n"
-    "the open project.";
-    int c = fl_choice(msg.c_str(), "Cancel", "Merge", 0,
-                      code_filename.c_str(), proj_filename.c_str(),
+    pos += snprintf(msg + pos, sizeof(msg) - pos,
+                    "\n\nClick Cancel to abort the MergeBack operation.\n"
+                    "Click Merge to merge all code changes back into\n"
+                    "the open project.");
+    int c = fl_choice(msg, "Cancel", "Merge", 0,
+                      code_filename, proj_filename,
                       num_changed_code, num_uid_not_found,
                       num_changed_structure, num_possible_override);
     if (c==0) return -1;
@@ -242,8 +247,14 @@ int Mergeback::ask_user_to_merge(const std::string &code_filename, const std::st
 void Mergeback::analyse_callback(unsigned long code_crc, unsigned long tag_crc, int uid) {
   Node *tp = proj_.tree.find_by_uid(uid);
   if (tp && tp->is_true_widget()) {
-    std::string cb = tp->callback(); cb += "\n";
-    unsigned long project_crc = fld::io::Code_Writer::block_crc(cb.c_str());
+    const char *cb = tp->callback();
+    size_t len = cb ? strlen(cb) : 0;
+    char *cb_nl = (char*)malloc(len + 2);
+    if (cb && len) memcpy(cb_nl, cb, len);
+    cb_nl[len] = '\n';
+    cb_nl[len + 1] = '\0';
+    unsigned long project_crc = fld::io::Code_Writer::block_crc(cb_nl);
+    free(cb_nl);
     // check if the code and project crc are the same, so this modification was already applied
     if (project_crc!=code_crc) {
       num_changed_code++;
@@ -264,8 +275,14 @@ void Mergeback::analyse_callback(unsigned long code_crc, unsigned long tag_crc,
 void Mergeback::analyse_code(unsigned long code_crc, unsigned long tag_crc, int uid) {
   Node *tp = proj_.tree.find_by_uid(uid);
   if (tp && tp->is_a(FLD_NODE_TYPE_Code)) {
-    std::string code = tp->name(); code += "\n";
-    unsigned long project_crc = fld::io::Code_Writer::block_crc(code.c_str());
+    const char *code = tp->name();
+    size_t len = code ? strlen(code) : 0;
+    char *code_nl = (char*)malloc(len + 2);
+    if (code && len) memcpy(code_nl, code, len);
+    code_nl[len] = '\n';
+    code_nl[len + 1] = '\0';
+    unsigned long project_crc = fld::io::Code_Writer::block_crc(code_nl);
+    free(code_nl);
     // check if the code and project crc are the same, so this modification was already applied
     if (project_crc!=code_crc) {
       num_changed_code++;
@@ -468,10 +485,18 @@ int Mergeback::analyse() {
 int Mergeback::apply_callback(long block_end, long block_start, unsigned long code_crc, int uid) {
   Node *tp = proj_.tree.find_by_uid(uid);
   if (tp && tp->is_true_widget()) {
-    std::string cb = tp->callback(); cb += "\n";
-    unsigned long project_crc = fld::io::Code_Writer::block_crc(cb.c_str());
+    const char *cb = tp->callback();
+    size_t len = cb ? strlen(cb) : 0;
+    char *cb_nl = (char*)malloc(len + 2);
+    if (cb && len) memcpy(cb_nl, cb, len);
+    cb_nl[len] = '\n';
+    cb_nl[len + 1] = '\0';
+    unsigned long project_crc = fld::io::Code_Writer::block_crc(cb_nl);
+    free(cb_nl);
     if (project_crc!=code_crc) {
-      tp->callback(read_and_unindent_block(block_start, block_end).c_str());
+      char *block = read_and_unindent_block(block_start, block_end);
+      tp->callback(block);
+      free(block);
       return 1;
     }
   }
@@ -484,10 +509,18 @@ int Mergeback::apply_callback(long block_end, long block_start, unsigned long co
 int Mergeback::apply_code(long block_end, long block_start, unsigned long code_crc, int uid) {
   Node *tp = proj_.tree.find_by_uid(uid);
   if (tp && tp->is_a(FLD_NODE_TYPE_Code)) {
-    std::string cb = tp->name(); cb += "\n";
-    unsigned long project_crc = fld::io::Code_Writer::block_crc(cb.c_str());
+    const char *code = tp->name();
+    size_t len = code ? strlen(code) : 0;
+    char *code_nl = (char*)malloc(len + 2);
+    if (code && len) memcpy(code_nl, code, len);
+    code_nl[len] = '\n';
+    code_nl[len + 1] = '\0';
+    unsigned long project_crc = fld::io::Code_Writer::block_crc(code_nl);
+    free(code_nl);
     if (project_crc!=code_crc) {
-      tp->name(read_and_unindent_block(block_start, block_end).c_str());
+      char *block = read_and_unindent_block(block_start, block_end);
+      tp->name(block);
+      free(block);
       return 1;
     }
   }
@@ -555,11 +588,11 @@ int Mergeback::apply() {
             FD_MERGEBACK_APPLY_IF_SAFE, or FD_MERGEBACK_APPLY
  \return -1 if an error was found in a tag
  \return -2 if no code file was found
- \return See more at ::merge_back(const std::string &s, int task).
+ \return See more at ::merge_back(const char *s, int task).
  */
-int Mergeback::merge_back(const std::string &s, const std::string &p, Task task) {
+int Mergeback::merge_back(const char *s, const char *p, Task task) {
   int ret = 0;
-  code = fl_fopen(s.c_str(), "rb");
+  code = fl_fopen(s, "rb");
   if (!code) return -2;
   do { // no actual loop, just make sure we close the code file
     if (task == FLD_MERGEBACK_TASK_ANALYSE) {
@@ -616,9 +649,9 @@ int Mergeback::merge_back(const std::string &s, const std::string &p, Task task)
  \return 2 if mergeback is called recursively
  \return 1 if the project filename is not available
  \return 0 if MergeBack is not enabled, or the result of the merge_back function.
- \see Mergeback::merge_back(const std::string &s, const std::string &p, Task task)
+ \see Mergeback::merge_back(const char *s, const char *p, Task task)
  */
-int mergeback_code_files(Project &proj, Mergeback::Feedback feedback)
+int mergeback_code_files(fld::Project &proj, Mergeback::Feedback feedback)
 {
   static bool recursion_lock = false;
   if (recursion_lock) return 2;
diff --git a/fluid/proj/mergeback.h b/fluid/proj/mergeback.h
index 48cc4e400..04a9dc902 100644
--- a/fluid/proj/mergeback.h
+++ b/fluid/proj/mergeback.h
@@ -21,17 +21,11 @@
 
 #include <stdint.h>
 #include <stdio.h>
-#include <string>
-
-namespace fld {
-
-class Project;
-
-namespace proj {
 
+namespace fld { class Project; }
 
 /** Class that implements the MergeBack functionality.
- \see merge_back(const std::string &s, int task)
+ \see merge_back(const char *s, int task)
  */
 enum {
   FLD_MERGEBACK_TAG_GENERIC = 0,
@@ -56,7 +50,7 @@ public:
   enum Feedback { QUIET = 0, CHATTY = 1 };
 protected:
   /// Apply mergeback for this project.
-  Project &proj_;
+  fld::Project &proj_;
   /// Pointer to the C++ code file.
   FILE *code;
   /// Current line number in the C++ code file.
@@ -73,7 +67,7 @@ protected:
   int num_possible_override;
 
   void unindent(char *s);
-  std::string read_and_unindent_block(long start, long end);
+  char *read_and_unindent_block(long start, long end);
   void analyse_callback(unsigned long code_crc, unsigned long tag_crc, int uid);
   void analyse_code(unsigned long code_crc, unsigned long tag_crc, int uid);
   int apply_callback(long block_end, long block_start, unsigned long code_crc, int uid);
@@ -86,20 +80,15 @@ protected:
   static bool read_tag(const char *tag, Tag *prev_type, uint16_t *uid, uint32_t *crc);
 
 public:
-  Mergeback(Project &proj);
+  Mergeback(fld::Project &proj);
   ~Mergeback();
-  int merge_back(const std::string &s, const std::string &p, Task task);
-  int ask_user_to_merge(const std::string &s, const std::string &p);
+  int merge_back(const char *s, const char *p, Task task);
+  int ask_user_to_merge(const char *s, const char *p);
   int analyse();
   int apply();
   static void print_tag(FILE *out, Tag prev_type, Tag next_type, uint16_t uid, uint32_t crc);
 };
 
-extern int merge_back(const std::string &s, const std::string &p, int task);
-
-} // namespace proj
-} // namespace fld
-
 extern void start_auto_mergeback();
 extern void mergeback_on_load();
 
diff --git a/fluid/proj/undo.cxx b/fluid/proj/undo.cxx
index 01d1b68c2..e4ee89bf6 100644
--- a/fluid/proj/undo.cxx
+++ b/fluid/proj/undo.cxx
@@ -103,7 +103,7 @@ void Undo::redo() {
     return;
   }
   if (reload_panel) {
-    for (auto w: Fluid.proj.tree.all_selected_widgets()) {
+    for (Widget_Node *w: Fluid.proj.tree.all_selected_widgets()) {
       w->open();
     }
   }
diff --git a/fluid/widgets/Node_Browser.cxx b/fluid/widgets/Node_Browser.cxx
index cf036f9b7..3343d6772 100644
--- a/fluid/widgets/Node_Browser.cxx
+++ b/fluid/widgets/Node_Browser.cxx
@@ -393,28 +393,28 @@ void Node_Browser::item_draw(void *v, int X, int Y, int, int) const {
   // Indent=12 per level: Now write the text that comes after the graphics representation
   Y += comment_incr;
   if (l->is_widget() || l->is_class()) {
-    std::string c = subclassname(l);
-    if (c.compare(0, 3, "Fl_")==0) c.erase(0, 3);
+    const char *c = subclassname(l);
+    if (c && strncmp(c, "Fl_", 3)==0) c += 3;
     // -- class
     fl_font(class_font, textsize());
     if (l->new_selected) fl_color(fl_contrast(class_color, FL_SELECTION_COLOR));
     else fl_color(class_color);
-    fl_draw(c.c_str(), X, Y+13);
-    X += int(fl_width(c.c_str())+fl_width('n'));
+    fl_draw(c, X, Y+13);
+    X += int(fl_width(c)+fl_width('n'));
     c = l->name() ? l->name() : "";
-    if (!c.empty()) {
+    if (c && c[0]) {
       // -- name
       fl_font(name_font, textsize());
       if (l->new_selected) fl_color(fl_contrast(name_color, FL_SELECTION_COLOR));
       else fl_color(name_color);
-      fl_draw(c.c_str(), X, Y+13);
+      fl_draw(c, X, Y+13);
     } else if (l->label()) {
       // -- label
       c = l->label();
       fl_font(label_font, textsize());
       if (l->new_selected) fl_color(fl_contrast(label_color, FL_SELECTION_COLOR));
       else fl_color(label_color);
-      copy_trunc(buf, c.c_str(), 32, 1, 0); // quoted string
+      copy_trunc(buf, c, 32, 1, 0); // quoted string
       fl_draw(buf, X, Y+13);
     }
   } else {