pre-C++11 compilers

[coypu%sdf.org@localhost]

Hi,

currently things are pretty bad if you are using pkgsrc without a C++11
compiler. I have attached a diff to make USE_LANGUAGES=c++11 imply
GCC_REQD+=4.8 for the GCC case, which is probably the right thing as
multiple GCC_REQD values behave correctly.

What I don't understand is how -std=c++11 ends up being appended to
packages like poppler and harfbuzz when they themselves do not have
USE_LANGUAGES=c++11, so I don't think my change is helping.

I'd like to apply GCC_REQD+=4.8 whenever this happens.

Any ideas?

More invasive change - require GCC 4.8 for GCC users, if USE_LANGUAGES=c++11
is used. GCC_REQD can include multiple values successfully, but this change
is considerably more likely to break.

Index: compiler/gcc.mk
===================================================================
RCS file: /cvsroot/pkgsrc/mk/compiler/gcc.mk,v
retrieving revision 1.179
diff -u -r1.179 gcc.mk
--- compiler/gcc.mk	25 Jun 2017 01:41:15 -0000	1.179
+++ compiler/gcc.mk	1 Jul 2017 09:20:21 -0000
@@ -101,6 +101,10 @@
 GCC_REQD+=	3.0
 .endif
 
+.if !empty(USE_LANGUAGES:Mc++11) || !empty(USE_LANGUAGES:Mgnu++11)
+GCC_REQD+=	4.8
+.endif
+
 # Only one compiler defined here supports Ada: lang/gcc5-aux
 # If the Ada language is requested, force lang/gcc5-aux to be selected
 .if !empty(USE_LANGUAGES:Mada)