Application to showcase build problem when including mbed.h from .cpp and .c -files. Folder structure and nested #includes inside #ifndefX+#defineX+#endif obfuscate the reason. Compiler error is about 'keyword namespace not found', which happens when mbed.h is included from .c.

Revision:
0:7c2be109ea78
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Tue Sep 27 07:13:58 2016 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#21dd7008a1540c02150f1b87c12294301db979bb