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#include <utility>
#include <cstdio>
// Uncommenting the next line will disable "signed/unsigned comparison" warnings:
// #pragma GCC diagnostic ignored "-Wsign-compare"
int main() {
static_assert(sizeof(int) == 4); // precondition
// Quite surprisingly
static_assert(-1 > 1U ); //< warning: sign-unsign comparison
// because after implicit conversion of -1 to the RHS type (`unsigned int`)
// the expression is equivalent to:
static_assert(0xFFFFFFFFU > 1U);
static_assert(0xFFFFFFFFU == static_cast<unsigned>(-1));
// In contrast, the cmp_* family compares integers as most expected -
// negative signed integers always compare less than unsigned integers:
static_assert(std::cmp_less( -1, 1U ));
static_assert(std::cmp_less_equal( -1, 1U ));
static_assert(!std::cmp_greater( -1, 1U ));
static_assert(!std::cmp_greater_equal( -1, 1U));
static_assert(-1 == 0xFFFFFFFFU); //< warning: sign-unsign comparison
static_assert(std::cmp_not_equal(-1, 0xFFFFFFFFU ));
printf("done\n");
return 0;
}
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