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* [Bug c++/67150] New: [c++-concepts] Expression constraint fails with dependent types
@ 2015-08-07 22:01 Casey at Carter dot net
0 siblings, 0 replies; only message in thread
From: Casey at Carter dot net @ 2015-08-07 22:01 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67150
Bug ID: 67150
Summary: [c++-concepts] Expression constraint fails with
dependent types
Product: gcc
Version: c++-concepts
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: Casey at Carter dot net
Target Milestone: ---
r226725 fails to compile this program:
#include <type_traits>
template <class From, class To>
concept bool ExplicitlyConvertible =
requires (From&& val) {
requires std::is_same<From,bool>::value;
requires std::is_same<To,bool>::value;
requires std::is_same<decltype(val),bool&&>::value;
static_cast<bool>((bool&&)val); // Line 9
static_cast<To>((From&&)val); // Line 10
};
template <class T>
concept bool Boolean =
requires (const T& t) {
{ t } -> ExplicitlyConvertible<bool>;
};
constexpr bool f(Boolean) { return true; } // Line 19
static_assert(f(true)); // Line 20
with error:
~/concept-gcc-r226725/bin/g++ -std=gnu++1z foo.cpp -c
foo.cpp:20:21: error: cannot call function ‘constexpr bool f(auto:1) [with
auto:1 = bool]’
static_assert(f(true)); // Line 20
^
foo.cpp:19:16: note: constraints not satisfied
constexpr bool f(Boolean) { return true; } // Line 19
^
foo.cpp:19:16: note: concept ‘Boolean<bool>’ was not satisfied
It does compile correctly if line 10 is commented out, demonstrating that the
expression "static_cast<To>((From&&)val)" is causing the constraint
dissatisfaction despite the fact that From is bool, To is bool, and
"static_cast<bool>((bool&&)val)" is acceptable.
>From gcc-bugs-return-494383-listarch-gcc-bugs=gcc.gnu.org@gcc.gnu.org Fri Aug 07 22:13:48 2015
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From: "mikael at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/48997] Don't use allocatable arrays for function elimination
Date: Fri, 07 Aug 2015 22:13:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?idH997
Mikael Morin <mikael at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |mikael at gcc dot gnu.org
--- Comment #1 from Mikael Morin <mikael at gcc dot gnu.org> ---
Thomas, what is the status of this?
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