Fix an issue with Boost compilation.

The issue is that when these macros are defined, libcxx
creates inline functions and so we end up with 2 separate
defintions of these functions (one inline in std and one
that is extern "C").

We undef these until libcxx is fixed. Without this,
some things can fail to compile correctly, like
Boost. Fixes issue #1716.

1 files changed, 17 insertions, 0 deletions

diff --git a/tests/test_core.py b/tests/test_core.py
index dd5b1e39..b766ac74 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -2949,6 +2949,23 @@ Exiting setjmp function, level: 0, prev_jmp: -1
       '''
       self.do_run(src, '3.14159')
 
+  def test_iswdigit(self):
+      if self.emcc_args is None: return self.skip('no libcxx inclusion without emcc')
+
+      src = '''
+        #include <stdio.h>
+        #include <cctype>
+        #include <cwctype>
+
+        int main() {
+          using namespace std;
+          printf("%d ", isdigit('0'));
+          printf("%d ", iswdigit(L'0'));
+          return 0;
+        }
+      '''
+      self.do_run(src, '1 1')
+
   def test_polymorph(self):
       if self.emcc_args is None: return self.skip('requires emcc')
       src = '''