8 karma · joined December 13, 2015
Anna, 24 - Student. Alessandro, 30 - Doctor. Federico, 32 - Professor. Martino, 27 - Doctor.
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C preprocessor based compile time hash from lolengine:
http://lolengine.net/blog/2011/12/20/cpp-constant-string-has...
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#define H1(s,i,x)(x65599u+(uint8_t)s[(i) <strlen(s)?strlen(s)-1-(i):strlen(s)])
#define H4(s,i,x) H1(s,i,H1(s,i+1,H1(s,i+2,H1(s,i+3,x))))
#define H16(s,i,x) H4(s,i,H4(s,i+4,H4(s,i+8,H4(s,i+12,x))))
#define H64(s,i,x) H16(s,i,H16(s,i+16,H16(s,i+32,H16(s,i+48,x))))
#define H256(s,i,x) H64(s,i,H64(s,i+64,H64(s,i+128,H64(s,i+192,x))))
#define HASH(s) ((uint32_t)(H256(s,0,0)^(H256(s,0,0)>>16)))
template<size_t N> constexpr uint32_t h(char const (&s)[N]) { return HASH(s); }
constexpr uint32_t h(const char s) { return HASH(s); }
uint32_t h(const std::string& s) { return h(s.c_str()); }
int main(int argc, const char argv) {
auto s = "keep";
std::string x = "simple";
switch(h(x))
{
case h("keep") : std::cout << "keep"; break;
case h("it") : std::cout << "it"; break;
case h("simple"): std::cout << "simple"; break;
};Said that I'm going next week to Chicago.