Re: [boost] Detection of 64bit using macro

Subject: Re: [boost] Detection of 64bit using macro
From: John Maddock (boost.regex_at_[hidden])
Date: 2010-08-14 08:05:19

>> 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.

John.