disable concepts since we don't have c++20

c_os/Makefile

@@ -71,7 +71,8 @@ ASM = nasm
 CC ?= gcc
 CXX ?= g++
 CFLAGS := $(CFLAGS) -m32 -march=i486 -Wall -fno-stack-protector -nostdlib -I. -g -ffreestanding -fno-pie -fno-pic -mpreferred-stack-boundary=2 -Wno-write-strings -mno-sse -mno-sse2 -mmanual-endbr
-CXXFLAGS := $(CFLAGS) -Wno-non-virtual-dtor -fno-threadsafe-statics -fno-use-cxa-atexit -fno-rtti -fno-exceptions -std=c++20
+CXXFLAGS := $(CFLAGS) -Wno-non-virtual-dtor -fno-threadsafe-statics -fno-use-cxa-atexit -fno-rtti -fno-exceptions
+# Needed for template concepts, but we don't have it available: -std=c++20
 
 BOOT = ../boot
 TOOLS = ../tools

c_os/devices/CGA_Stream.h

@@ -55,6 +55,7 @@ public:
 
     // NOTE: I added this
     template<typename T>
+    // requires std::derived_from<T, CGA_Stream>
     friend T& operator<<(T& os, const fgc& fg) {
         os.flush();
         os.color_fg = fg.fg;
@@ -62,6 +63,7 @@ public:
     }
 
     template<typename T>
+    // requires std::derived_from<T, CGA_Stream>
     friend T& operator<<(T& os, const bgc& bg) {
         os.flush();
         os.color_fg = bg.bg;

c_os/lib/OutStream.h

@@ -23,7 +23,7 @@
 #define __OutStream_include__
 
 #include "lib/StringBuffer.h"
-#include <concepts>
+// #include <concepts> // NOTE: Only available in c++20
 
 // NOTE: I added this
 class fillw {
@@ -77,9 +77,13 @@ public:
     //       This allows chaining of operator<< of different streams.
     //       Needed because I added operator<< overloads to the CGA_Stream class to change color with manipulators.
 
+    // NOTE: The templace concepts are only available in c++20.
+    //       Leaving them out makes this unsafe, but it doesn't matter as much in this case since we only
+    //       use a CGA_Stream in Globals.h anyway.
+
     // Darstellung eines Zeichens (trivial)
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, char c) {
         os.put(c);
         if (c != '\n') {
@@ -90,14 +94,14 @@ public:
     }
 
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, unsigned char c) {
         return os << (char)c;
     }
 
     // Darstellung einer nullterminierten Zeichenkette
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, char* string) {
 
         char* pos = string;
@@ -111,31 +115,31 @@ public:
 
     // Darstellung ganzer Zahlen im Zahlensystem zur Basis base
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, short ival) {
         return os << (long)ival;
     }
 
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, unsigned short ival) {
         return os << (unsigned long)ival;
     }
 
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, int ival) {
         return os << (long)ival;
     }
 
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, unsigned int ival) {
         return os << (unsigned long)ival;
     }
 
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, long ival) {
         // Bei negativen Werten wird ein Minuszeichen ausgegeben.
         if (ival < 0) {
@@ -147,7 +151,7 @@ public:
     }
 
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, unsigned long ival) {
         unsigned long div;
         char digit;
@@ -179,7 +183,7 @@ public:
 
     // Darstellung eines Zeigers als hexadezimale ganze Zahl
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, void* ptr) {
         int oldbase = os.base;
         os.base = 16;
@@ -191,14 +195,14 @@ public:
     // Aufruf einer Manipulatorfunktion
     // NOTE: Changed the function pointer type including the manipulator functions
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, T& (*f)(T&)) {
         return f(os);
     }
 
     // NOTE: I added this
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, const fillw& w) {
         os.flush();  // Flush the buffer to not modify previous output
         os.fill_width = w.w;
@@ -206,7 +210,7 @@ public:
     }
 
     template<typename T>
-    requires std::derived_from<T, OutStream>
+    // requires std::derived_from<T, OutStream>
     friend T& operator<<(T& os, const fillc& c) {
         os.flush();
         os.fill_char = c.c;