Pointer to consteval function not allowed in default argument to consteval function

[llvmbot]

Bugzilla Link	47714
Resolution	DUPLICATE
Resolved on	Oct 21, 2021 06:09
Version	trunk
OS	All
Reporter	LLVM Bugzilla Contributor
CC	@AaronBallman,@efriedma-quic,@zygoloid,@synopsys-sig-compiler-frontends

Extended Description

The following example is given both in the current C++ draft standard: http://eel.is/c++draft/expr.const#11 and the immediate functions proposal: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1073r3.html

consteval int f() { return 42; }
consteval auto g() { return f; }
consteval int h(int (*p)() = g()) { return p(); }
constexpr int r = h(); // OK

and although examples not normative AFAICT this is meant to be valid but clang rejects this although gcc does accept it, see the following godbolt: https://godbolt.org/z/WW7G9q

[AaronBallman]

*** This bug has been marked as a duplicate of bug llvm/llvm-bugzilla-archive#48886 ***

[andreasfertig]

mentioned in issue llvm/llvm-bugzilla-archive#48886