use a char32_t character in the base Stream class

Add an operator<<(char32_t) to the Stream class, char32_t will be used
as a main character instead of a wchar_t (this is needed on systems
where sizeof(wchar_t) is equal to 2).

while here:
- add to utf8:
  size_t wide_to_int(const Stream & stream, size_t stream_index, int & res, bool & correct)
  template<typename StreamType, typename OutputFunction> bool wide_to_output_function(StreamType & buffer, OutputFunction output_function, int mode = 1)
  template<typename OutputFunction> bool wide_to_output_function_by_index(const Stream & stream, OutputFunction output_function, int mode)
- add to convert/misc:
  bool try_esc_to_tex(char32_t c, pt::Stream & out)
  bool try_esc_to_html(char32_t c, pt::Stream & out)

src/log/log.cpp

@@ -5,7 +5,7 @@
  */
 
 /*
- * Copyright (c) 2018-2022, Tomasz Sowa
+ * Copyright (c) 2018-2024, Tomasz Sowa
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -274,6 +274,17 @@ Log & Log::operator<<(wchar_t val)
 }
 
 
+Log & Log::operator<<(char32_t val)
+{
+	if( buffer && file_log && current_level <= file_log->get_log_level() )
+	{
+		(*buffer) << val;
+	}
+
+	return *this;
+}
+
+
 Log & Log::operator<<(bool val)
 {
 	if( can_put_log() )

src/log/log.h

@@ -100,6 +100,7 @@ public:
 	Log & operator<<(char val);
 	Log & operator<<(unsigned char val);
 	Log & operator<<(wchar_t val);
+	Log & operator<<(char32_t val);
 	Log & operator<<(bool val);
 	Log & operator<<(short val);
 	Log & operator<<(int s);