No-overflow cast on x64
- by Cheeso
I have an existing C codebase that works on x86.
I'm now compiling it for x64.
What I'd like to do is cast a size_t to a DWORD, and throw an exception if there's a loss of data.
Q: Is there an idiom for this?
Here's why I'm doing this:
A bunch of Windows APIs accept DWORDs as arguments, and the code currently assumes sizeof(DWORD)==sizeof(size_t). That assumption holds for x86, but not for x64. So when compiling for x64, passing size_t in place of a DWORD argument, generates a compile-time warning.
In virtually all of these cases the actual size is not going to exceed 2^32. But I want to code it defensively and explicitly.
This is my first x64 project, so... be gentle.
