diff options
Diffstat (limited to 'libstdc++-v3/testsuite/26_numerics/lcm/105844.cc')
-rw-r--r-- | libstdc++-v3/testsuite/26_numerics/lcm/105844.cc | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/libstdc++-v3/testsuite/26_numerics/lcm/105844.cc b/libstdc++-v3/testsuite/26_numerics/lcm/105844.cc new file mode 100644 index 00000000000..d0e032e03e0 --- /dev/null +++ b/libstdc++-v3/testsuite/26_numerics/lcm/105844.cc @@ -0,0 +1,22 @@ +// { dg-do compile { target c++17 } } +#include <numeric> +#include <climits> + +// PR libstdc++/105844 + +// |INT_MIN| can be represented in common_type_t<int, unsigned> i.e. unsigned. +static_assert( std::lcm(INT_MIN, 1u) == INT_MAX+1u ); +static_assert( std::lcm(1u, INT_MIN) == INT_MAX+1u ); + +// But |INT_MIN| cannot be represented in common_type<int, int> i.e. int. +constexpr int a = std::lcm(INT_MIN, 1); // { dg-error "overflow" } +constexpr int b = std::lcm(1, INT_MIN); // { dg-error "overflow" } + +// And the LCM of 50000 and 49999 cannot be represented in int. +constexpr int c = std::lcm(50000, 49999); // { dg-error "overflow" } +constexpr int d = std::lcm(49999, 50000); // { dg-error "overflow" } + +// Similarly for unsigned, but the diagnostic is a failed assertion instead. +constexpr int e = std::lcm(500000u, 499999); // { dg-error "in 'constexpr'" } +constexpr int f = std::lcm(499999u, 500000); // { dg-error "in 'constexpr'" } +// { dg-error "unreachable" "" { target *-*-* } 0 } |