BUG: Zero (complex) to the power of zero (label/scalar) does not follow Gcc/Clang
Summary
There is no agreed value for zero to the power of zero in C++ standard, but C99.
Despite this, Gcc and Clang implementations assume Type(0)^0 = 1.
In OpenFOAM, when Type=complex, the assumption is not followed even though Foam::pow is based on std::pow. When Type=scalar, the above assumption is followed.
Steps to reproduce
Test-A.tar.gz produces the following:
# FOAM: complex(0)^0 #
Foam::pow(Foam::complex, label) = (-nan -nan)
Foam::pow(Foam::complex, scalar) = (-nan -nan)
std::pow(std::complex, label) = (-nan -nan)
std::pow(std::complex, scalar) = (-nan -nan)
# std: complex(0)^0 #
std::complex(scalar,scalar)^scalar = (1,0)
# FOAM: scalar(0)^0 #
Foam::pow(scalar, label) = 1
Foam::pow(scalar, scalar) = 1
# std: scalar(0)^0 #
std::pow(scalar, label) = 1
std::pow(scalar, scalar) = 1What is the expected correct behavior?
Foam::pow should return whatever std::pow returns for complex types.
Environment information
- OpenFOAM version : dev
- Operating system : osuse
- Compiler : gcc 7