D int and C/C++ int etc not really compatible when interfacing to C/C++

[John Colvin via Digitalmars-d-learn]

On Saturday, 1 November 2014 at 15:00:57 UTC, Shriramana Sharma 
via Digitalmars-d-learn wrote:
> In the following pages:
>
> http://dlang.org/interfaceToC.html
> http://dlang.org/cpp_interface
>
> the "Data Type Compatibility" section says D int is compatible 
> with
> C/C++ int. Isn't this actually false because D's integer types 
> are
> fixed-size whereas C/C++'s are variable? So D int is only 
> compatible
> with C++ int32_t, and who knows what that is typedef-ed to? 
> Likewise
> for uint, long, short etc.
>
> So how to ensure, when calling C/C++, that the D int etc are 
> being
> mapped to the correctly-sized C/C++ type? Does the compiler 
> ensure
> that since the compatibility is being advertised as built-in?

Note this at the end of the "Data Type Compatiblity" section:

"These equivalents hold for most C compilers. The C standard does 
not pin down the sizes of the types, so some care is needed."

D's built-in types do not change based on the companion C 
compiler. When linking to C, it is the programmers responsibility 
to ensure they are using the right types.

core.stdc.config can help deal with the most common 
inconsistencies.