WIP crc32 in TMP

tmp.cpp

/**
 * We need string length - not "hard"
 */
template<const char text[]>
struct tmp_strlen
{
    template<const char v, const int index>
    struct tmp_strlen_
    {
        enum _strlen
        {
            value = tmp_strlen_<text[index + 1], index + 1>::value
        };
    };
    
    template<const int index>
    struct tmp_strlen_<'\0', index>
    {
        enum _strlen
        {
            value = index
        };
    };
    
    
    enum _strlen
    {
        value = tmp_strlen_<text[0], 0>::value
    };
};

/**
 * Okay - now for the crc32 ... which I don't actually remember off the top of my head
 */
template<const char text[]>
struct tmp_crc
{
    enum _crc : unsigned int
    {
        value = tmp_strlen<text>::value
    };
};

/**
 * Macro - we need to declare these suckers as global constants
 */
#define HASH_ID(name, string) \
    constexpr const char _HASH_ID##name[] = string;  \
    constexpr const unsigned int name = tmp_crc< _HASH_ID##name >::value

/**
 * Test program below ...
 */
#include <iostream>
#include <string>
#include <vector>

#include <cstdint>




HASH_ID(foo, "foobar");

constexpr const char g_unique_name[] = "hello";


template<const char text[]>
struct hash_sum
{
    enum _values
    {
        length = tmp_strlen<g_unique_name>::value,
        
        crc = sizeof(text),
    };
};





int main()
{
    std::cout << "heldhgorld!\n";
    std::cout << "foo<\"hello\">::crc = " << hash_sum<g_unique_name>::crc << std::endl;
    std::cout << "foo<\"hello\">::length = " << hash_sum<g_unique_name>::length << std::endl;
    std::cout << "foo = " << foo << std::endl;
    
    return(EXIT_SUCCESS);
}