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view gcc/testsuite/g++.dg/cpp2a/is-constant-evaluated9.C @ 145:1830386684a0
gcc-9.2.0
author | anatofuz |
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date | Thu, 13 Feb 2020 11:34:05 +0900 |
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// PR c++/91428 - warn about std::is_constant_evaluated in if constexpr. // { dg-do compile { target c++2a } } // { dg-options "-Wtautological-compare" } namespace std { constexpr inline bool is_constant_evaluated () noexcept { return __builtin_is_constant_evaluated (); } } constexpr int foo(int i) { if constexpr (std::is_constant_evaluated ()) // { dg-warning ".std::is_constant_evaluated. always evaluates to true in .if constexpr." } return 42; else return i; } constexpr int foo2(int i) { if constexpr (__builtin_is_constant_evaluated ()) // { dg-warning ".std::is_constant_evaluated. always evaluates to true in .if constexpr." } return 42; else return i; } constexpr int foo3(int i) { // I is not a constant expression but we short-circuit it. if constexpr (__builtin_is_constant_evaluated () || i) return 42; else return i; } constexpr int foo4(int i) { const int j = 0; if constexpr (j && __builtin_is_constant_evaluated ()) return 42; else return i; }