I want to create a function to simplify a list/vector. I can do it in python:

i = [1, 2, 3, 4, 5]
f = [1.1, 2.2, 3.3, 4.4, 5.5]
s = ["one", "two", "three", "four", "five"]
def simplify(lst):
    if len(lst) == 0:
        return 0
    tmp = lst[0]
    for x in range(1, len(lst)):
        tmp  = lst[x]
    print(tmp)
    return tmp
simplify(i)
simplify(f)
simplify(s)

but for c I would have to write the same function for many variable types (long long, double, int, string, char). My question is, can I do in c like I did in python? (creating a single function for multiple types)

CodePudding user response：

My question is, can I do in c like I did in python? (creating a single function for multiple types)

Almost. A C function template is not a function, but using one can look indistinguishable from it.

You will also struggle with your choice of -1 as the result if the sequence is empty, as -1 is not a string.

template <typename Range>
std::ranges::range_value_t<Range> simplify(Range && range) {
    auto it = std::ranges::begin(range);
    if (it == std::ranges::end(range)) return -1; // this will fail for strings

    auto result = *it  ;
    for (; it != std::ranges::end(range);   it) {
        result  = *it;
    }
    std::cout << result; // I assume this is for testing the function?
    return result;
}

If you make a different choice about what to do with an empty input, there is a function very similar to yours in the standard library:

template <typename Range>
std::ranges::range_value_t<Range> simplify(Range && range) {
    std::ranges::range_value_t<Range> zero {}; // 0 for numbers, empty string for strings, etc.
    return std::accumulate(std::ranges::begin(range), std::ranges::end(range), zero); 
}

int main() {
    std::vector<int> i {1, 2, 3, 4, 5};
    std::vector<double> f {1.1, 2.2, 3.3, 4.4, 5.5};
    std::vector<std::string> s {"one", "two", "three", "four", "five"};
    std::cout << simplify(i);
    std::cout << simplify(f);
    std::cout << simplify(s);
}

See it on coliru