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From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug libstdc++/55993] tuple_cat not a constant expression for result size >= 3
Date: Tue, 15 Jan 2013 17:29:00 -0000
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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55993

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> 2013-01-15 17:28:42 UTC ---
#include <tuple>
struct A {};
constexpr auto t = std::make_tuple( A(), A() );
constexpr auto a = std::get<0>( t );

t.cc:4:35: error: accessing value of 't' through a 'const A' glvalue in a
constant expression
 constexpr auto a = std::get<0>( t );
                                   ^

Huh?