How to create static method that evaluates local static variable once?
- by Viet
I have a class with static method which has a local static variable. I want that variable to be computed/evaluated once (the 1st time I call the function) and for any subsequent invocation, it is not evaluated anymore. How to do that? Here's my class:
template<
typename T1 = int, unsigned N1 = 1,
typename T2 = int, unsigned N2 = 0,
typename T3 = int, unsigned N3 = 0,
typename T4 = int, unsigned N4 = 0,
typename T5 = int, unsigned N5 = 0,
typename T6 = int, unsigned N6 = 0,
typename T7 = int, unsigned N7 = 0,
typename T8 = int, unsigned N8 = 0,
typename T9 = int, unsigned N9 = 0,
typename T10 = int, unsigned N10 = 0,
typename T11 = int, unsigned N11 = 0,
typename T12 = int, unsigned N12 = 0,
typename T13 = int, unsigned N13 = 0,
typename T14 = int, unsigned N14 = 0,
typename T15 = int, unsigned N15 = 0,
typename T16 = int, unsigned N16 = 0>
struct GroupAlloc
{
static const uint32_t sizeClass;
static uint32_t getSize()
{
static uint32_t totalSize = 0;
totalSize += sizeof(T1)*N1;
totalSize += sizeof(T2)*N2;
totalSize += sizeof(T3)*N3;
totalSize += sizeof(T4)*N4;
totalSize += sizeof(T5)*N5;
totalSize += sizeof(T6)*N6;
totalSize += sizeof(T7)*N7;
totalSize += sizeof(T8)*N8;
totalSize += sizeof(T9)*N9;
totalSize += sizeof(T10)*N10;
totalSize += sizeof(T11)*N11;
totalSize += sizeof(T12)*N12;
totalSize += sizeof(T13)*N13;
totalSize += sizeof(T14)*N14;
totalSize += sizeof(T15)*N15;
totalSize += sizeof(T16)*N16;
totalSize = 8*((totalSize + 7)/8);
return totalSize;
}
};