http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59819
Bug ID: 59819
Summary: -Wunused-value reports incorrect values as unused
Product: gcc
Version: 4.8.1
Status: UNCONFIRMED
Severity: trivial
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: caibbor at gmail dot com
Created attachment 31836
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=31836&action=edit
The program in full to replicate this bug
This is pretty trivial but the warning outputs incorrect information. given the
line:
int foo = static_cast< int >( 1, 2, 3 );
G++ reports that value 2 and 3 are not used, when in fact 1 and 2 are not used.
G++ 4.8.1's output (with -Wall):
test.cpp: In function ‘int main()’:
test.cpp:15:35: warning: left operand of comma operator has no effect
[-Wunused-value]
int foo = static_cast< int >( 1, 2, 3 );
^
test.cpp:15:38: warning: right operand of comma operator has no effect
[-Wunused-value]
int foo = static_cast< int >( 1, 2, 3 );
^
Clang 3.2.7 gets it right, however:
test.cpp:15:32: warning: expression result unused [-Wunused-value]
int foo = static_cast< int >( 1, 2, 3 );
^
test.cpp:15:35: warning: expression result unused [-Wunused-value]
int foo = static_cast< int >( 1, 2, 3 );
^
2 warnings generated.
