static_cast to double for pow
static_cast to double for pow

Windows (incorrectly) provides overloads for pow so that if T is not
double/float it won't compile

chr-engwer/Vc,chr-engwer/Vc,VcDevel/Vc,chr-engwer/Vc,VcDevel/Vc,VcDevel/Vc,VcDevel/Vc