http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53745
Bug #: 53745
Summary: Bitshifted value (1 << 31) within enumerator class is
calculated incorrectly during compilation.
Classification: Unclassified
Product: gcc
Version: 4.6.1
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassig...@gcc.gnu.org
ReportedBy: sbgcc...@yahoo.co.uk
When compiling an 'enum class' (-std=c++0x) that uses bit-shifted values, the
result of "1 << 31" is calculated incorrectly, resulting in -0x80000000
(*negative* 2^31) rather than the correct result of 0x80000000:
// *** BEGIN EXAMPLE CODE (main.cpp) ***
enum class EnumTest : unsigned long int
{
A = 1 << 30,
B = 1 << 31
};
int main()
{
return 0;
}
// *** END EXAMPLE CODE ***
// *** BEGIN gcc-4.6.1 OUTPUT ***
main.cpp|4|error: enumerator value -0x00000000080000000 is too large for
underlying type ‘long unsigned int’|
// *** END gcc-4.6.1 OUTPUT ***
