Created
August 10, 2018 17:01
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/* | |
Compile-time resolution of correct data type based on the platform differency. For example, if the code is compiled in a 32-bit machine, | |
integral_ptr_t is resolved into uint32_t. Reinterpreting the pointer, which is a void pointer, into uint32_t and dereferencing later back to, e.g. int*, | |
is a thorough valid operation. -> Refer to https://en.cppreference.com/w/cpp/language/reinterpret_cast for further information. | |
Reference: https://en.wikibooks.org/wiki/C%2B%2B_Programming/Templates/Template_Meta-Programming | |
*/ | |
#include <iostream> | |
#include <cstdint> | |
template <bool Condition,typename TrueResult, typename FalseResult> | |
class if_; | |
template <typename TrueResult,typename FalseResult> | |
struct if_<true,TrueResult,FalseResult> | |
{ | |
typedef TrueResult result; | |
}; | |
template<typename TrueResult,typename FalseResult> | |
struct if_<false,TrueResult,FalseResult> | |
{ | |
typedef FalseResult result; | |
}; | |
int main(){ | |
typename if_<true,int,void*>::result number(3); | |
typename if_<false,int,void*>::result pointer(&number); | |
typedef typename if_<(sizeof(void *) > sizeof(uint32_t)),uint64_t,uint32_t>::result integral_ptr_t; | |
integral_ptr_t converted_pointer = reinterpret_cast<integral_ptr_t>(pointer); | |
std::cout<<*((int *)converted_pointer)<<std::endl; | |
} |
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