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* [Bug c++/45113] New: absent or confusing diagnostics of invalid template argument list in implicit template class instantiation
@ 2010-07-28 19:07 roman at binarylife dot net
0 siblings, 0 replies; only message in thread
From: roman at binarylife dot net @ 2010-07-28 19:07 UTC (permalink / raw)
To: gcc-bugs
$cat test1.cpp
template<typename X,typename Y> struct is_same { static bool const value=false;
};
template<typename X> struct is_same<X,X> { static bool const value=true; };
template<typename... X> struct U {};
struct Q { typedef U<int x,int y> C; };
typedef char check[is_same<int,Q::C>::value ? 1 : -1];
$g++ -std=gnu++0x -c test1.cpp && echo $?
0
In 14.3.1, the Standard says: "A template-argument for a template-parameter
which is a type shall be a type-id." The test must fail compilation, and Q::C
can not be int.
$cat test2.cpp
template<typename... X> struct U {};
typedef U<int x,int y> B;
$g++ -std=gnu++0x -c test2.cpp
test2.cpp:2:25: error: invalid type in declaration before ';' token
This message is confusing.
$cat test3.cpp
template<typename X,typename Y> struct U {};
typedef U<int x,int y> A;
$g++ -c test3.cpp
test3.cpp:2:22: error: wrong number of template arguments (1, should be 2)
test3.cpp:1:40: error: provided for 'template<class X, class Y> struct U'
test3.cpp:2:25: error: invalid type in declaration before ';' token
These messages are confusing.
--
Summary: absent or confusing diagnostics of invalid template
argument list in implicit template class instantiation
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: roman at binarylife dot net
GCC build triplet: x86_64-unknown-linux-gnu
GCC host triplet: x86_64-unknown-linux-gnu
GCC target triplet: x86_64-unknown-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=45113
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2010-07-28 19:07 [Bug c++/45113] New: absent or confusing diagnostics of invalid template argument list in implicit template class instantiation roman at binarylife dot net
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