Templated scanf-like function

callargs.cpp

#include <iostream>

struct SomeStruct {
    int val;
};

template<typename T>
bool
assign(const char c, T& ref) {
    return false;
}

bool
assign(const char c, bool*& ref) {
    if (c != 'b')
        return false;
    *ref = true;
    return true;
}

bool
assign(const char c, int*& ref) {
    if (c != 'i')
        return false;
    *ref = 42;
    return true;
}

bool
assign(const char c, SomeStruct& ref) {
    if (c != 'h')
        return false;
    ref.val = 81;
    return true;
}

template<typename T>
bool
tscanf(const char *format, const char *name, T& ref)
{
    if (format[0] == '\0' || format[1] != '\0') {
        std::cerr << "Wrong number of arguments" << std::endl;
        return false;
    }

    if (!assign(format[0], ref)) {
        std::cerr << "Wrong type for argument " << name << std::endl;
        return false;
    }

    return true;
}

template<typename T, typename... Args>
bool
tscanf(const char *format, const char *name, T& ref, Args... args)
{
    if (format[0] == '\0') {
        std::cerr << "Wrong number of arguments" << std::endl;
        return false;
    }

    if (!assign(format[0], ref)) {
        std::cerr << "Wrong type for argument " << name << std::endl;
        return false;
    }

    return tscanf(format + 1, args...);
}

int
main(void)
{
    bool b;
    int i;
    SomeStruct h;
    if (!tscanf("hbi",
        "handle", h,
        "switch", &b,
        "num", &i))
        return 1;
    std::cout << h.val << ' ' << b  << ' ' << i << std::endl;
    return 0;
}