On 08/14/2010 04:05 PM, John Maddock wrote:
the question might be not directly related to boost. But i just want to be sure that i am not reventing the wheel. I am searching for a macro that is able to detect that a system is 32bit or 64bit no matter what compiler is used. Is there something similar already implemented in boost?
There is no standard macro to detect this, so every solution will be platform-specific. For instance, I think, GCC defines some macro that has value of sizeof(void*). On platforms with uintptr_t you can test for UINTPTR_MAX macro value. On linux there is __WORDSIZE macro that has value of number of bits in the native integer type (that is, 32 or 64).
You also need to specifiy what you mean by "64 bit", do you mean 64-bit pointers, or 64-bit integers or both, or something else, as these can all vary independently of each other.
It's not that I disagree with you, but usually platforms are referred to as 64-bit when a program is able to address 64 bit address range, which means that the pointer type has to be at least 64-bit. The support for 64-bit integers is much less connected to the platform architecture.