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c++typesstdint

Usage of uintptr_t vs DWORD_PTR

Both are used for storing addresses and doing pointer arithmetic, both are defined in WinAPI, when should I use a uintptr_t (cstdint) vs a DWORD_PTR (Windows.h)? Both are 32bits and 64bits in x86 and x86_64 respectively

A DWORD_PTR is an unsigned long type used for pointer precision. It is used when casting a pointer to an unsigned long type to perform pointer arithmetic. DWORD_PTR is also commonly used for general 32-bit parameters that have been extended to 64 bits in 64-bit Windows.

I do not intend for my code to be portable, I'm stuck with WinAPI. What type is the best use case?

Solution

  • Prefer uintptr_t it is part of the C++ standard as of C++11 and later. DWORD_PTR is specific to Visual C++ and is therefore not portable.

    While Visual C++ may choose to implement uintptr_t as a DWORD_PTR or unsigned long under the hood, that is up to them to do, you are safer sticking to the standard library.