Are there any platforms where fixed width types (intXX_t) are missing?

C++11 has fixed width, 2's complement types: (u)int8_t, (u)int16_t, etc.

However, these types are optional.

Sometimes I need to use these types, so my code might be less portable because of this.

Is there any platform (with C+11 compiler available) currently, where these types don't exist?

Note 1: I know, that there is hardware which doesn't support these types. However, all such hardware I know doesn't have a C++11 conformant compiler. This question is about a C++11 implementation, where fixed width types are actually missing.

Note 2: I know, that there are mandatory least and fast types, but this question is about exact width types.