Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
528 views
in Technique[技术] by (71.8m points)

c++ - C++11: template parameter redefines default argument

When compiling the following source code with gcc there are no errors / warnings:

template< typename T = int > T func( );
template< typename T = int > T func( );

When I compile the same source code with clang++, I got the following error:

redeftempparam.cc:2:24: error: template parameter redefines default argument
template< typename T = int > T func( );
                       ^
redeftempparam.cc:1:24: note: previous default template argument defined here
template< typename T = int > T func( );
                       ^
1 error generated.

Command to compile

[clang++|g++] -Wall -Werror -std=c++11 redeftempparam.cc

(Version information: gcc 4.7.2, clang version 3.3 (trunk 171722))

My question:

Is this type of redefinition allowed? If not: can you please point me to the appropriate point in the C++ standard?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

§14.1.12:

A template-parameter shall not be given default arguments by two different declarations in the same scope.

[Example:

template<class T = int> class X;
template<class T = int> class X { /?... ?/ }; // error

— end example ]


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...