Modern C++.

Frankly I don't care to try to support a wide variety of
"older" stuff.  I don't have the time, and I don't think
it's sensible to promote being able to play the
modified form of this game (using my dynamic system) on
toasters and coffee makers.  Most systems with the capacity
to handle what I'll wind up demanding will probably
support C++23 already.

sc2/build/unix/build.config

@@ -462,6 +462,8 @@ uqm_process_config() {
 	# These allow use of C++ without the standard library
 	# ADAM: We're permitting ALL of C++!
 	#CXXFLAGS="$CXXFLAGS -fno-rtti -fno-exceptions -nostdinc++"
+	# Also use more modern C++
+	CXXFLAGS="$CXXFLAGS -std=c++2b"
 
 	# At this point, all the compiler flags must be set.
 	CFLAGS="$CFLAGS $CCOMMONFLAGS"