Convert type and non-type template arguments to a vector of strings

TemplateArgs.cpp

#include <type_traits>
#include <vector>
#include <string>
#include <algorithm>
#include <iostream>
#include <iterator>

typedef enum {
    ADD = 0,
    SUB
} Enum;

template<typename InputType>
std::string toString(InputType value) {
    return std::to_string(value);
}

template<>
std::string toString(bool p) {
    return (p ? "true" : "false");
}

template<>
std::string toString(Enum p) {
    const char* retVal = NULL;
#define CASE_STMT(v) \
    case v: retVal = #v; break
    switch (p) {
        CASE_STMT(ADD);
        CASE_STMT(SUB);
    }
#undef CASE_STMT
    return retVal;
}

template<typename T> struct TypeTraits;

template<>
struct TypeTraits<float> {
    using type = float;
    static const char* getName() { return "float"; }
};

template<typename... InstanceTypes>
struct TemplateArgs {
    template<typename... ArgsTypes>
    auto operator()(ArgsTypes... args) const {
        using std::vector;
        using std::string;
        using std::begin;
        using std::end;

        vector<string> typeParams = { TypeTraits<InstanceTypes>::getName()... };
        vector<string> nonTypeParams = { toString(args)... };
        typeParams.insert(std::end(typeParams),
            std::begin(nonTypeParams), std::end(nonTypeParams));
        return typeParams;
    }
};

int main() {
    TemplateArgs<float> types;
    for(auto str: types(2, false, ADD)) {
        std::cout<< str << std::endl;
    }
    return 0;
}