http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55783
Bug #: 55783
Summary: Warnings instead of compiler errors for narrowing
conversions within list-initializations
Classification: Unclassified
Product: gcc
Version: 4.7.2
Status: UNCONFIRMED
Severity: major
Priority: P3
Component: c++
AssignedTo: [email protected]
ReportedBy: [email protected]
Created attachment 29023
--> http://gcc.gnu.org/bugzilla/attachment.cgi?id=29023
Erroneous C++ 2011 program that has a narrowing conversion error.
Narrowing conversions for initializer lists are producing warnings instead of
errors in -std=c++11 mode. See standard 8.5.4 item 3:
If a narrowing conversion (see below) is required to convert any of the
arguments, the program is ill-formed.
and item 7:
A narrowing conversion is an implicit conversion...
from long double to double or float, or from double to float, except where
the source is a constant
expression and the actual value after conversion is within the range of
values that can be represented
(even if it cannot be represented exactly)
Compiling the attached program has the following output with -std=c++11:
test.cpp: In function ‘void f(double)’:
test.cpp:3:26: warning: narrowing conversion of ‘d’ from ‘double’ to ‘float’
inside { } [-Wnarrowing]
test.cpp:3:26: warning: narrowing conversion of ‘d’ from ‘double’ to ‘float’
inside { } [-Wnarrowing]
test.cpp:3:26: warning: narrowing conversion of ‘d’ from ‘double’ to ‘float’
inside { } [-Wnarrowing]
