meson: Relax MSVC version requirement to 2015

fanc999-1 · kjellahl · commit 2f87f7f246eb · 2019-12-24T10:46:51.000+01:00
libsigc++ requires a C++-11-compliant compiler, so we can just make the
build look for Visual Studio 2015 instead of Visual Studio 2017 15.7.

Visual Studio 2013 also works, but since it will spew out loads of
warnings and the latest C++-11 version of glibmm is not buildable with
Visual Studio 2013, let's just require Visual Studio 2015.
diff --git a/meson.build b/meson.build
@@ -92,11 +92,9 @@ benchmark_dep = dependency('boost', modules: ['system', 'timer'],
                            version: '>=1.20.0', required: do_benchmark)
 can_benchmark = benchmark_dep.found()
 
-if is_msvc
-  # We must have Visual Studio 2017 15.7 or later...
-  assert(cpp_compiler.version().split('.')[0].to_int() >= 19 and \
-         cpp_compiler.version().split('.')[1].to_int() >= 15,
-         'Visual Studio 2017 15.7 or later is required')
+# We must have Visual Studio 2015 or later...
+if is_msvc and cpp_compiler.version().version_compare('<19')
+  error('Visual Studio 2015 or later is required')
 endif
 
 # Some dependencies are required only in maintainer mode and/or
