cpp-course/modules/04_arrays_and_strings/src/std_string.cpp

#include "std_string.hpp"

#include <algorithm>
#include <locale>
#include <ranges>
#include <sstream>

namespace arrays {

auto to_uppercase(const std::string &text) -> std::string {
    // Returns copy of the string without mutating the original string
    auto s = std::string{text};
    auto c_to_upper = [](const unsigned char c) { return std::toupper(c); };
    std::ranges::transform(s, s.begin(), c_to_upper);
    return s;
}

auto trim(const std::string& text) -> std::string {
    // Returns a trimmed copy of the string
    auto s = std::string{text};
    auto is_not_space = [](const unsigned char c) { return !std::isspace(c); };
    const auto first = std::ranges::find_if(s, is_not_space);
    const auto last = std::ranges::find_if(s.rbegin(), s.rend(), is_not_space).base();
    s.erase(last, s.end());
    s.erase(s.begin(), first);
    return s;
}

auto replace_all(const std::string &text, const char from, const char to) -> std::string {
    // This one also copies the string
    auto s = std::string{text};
    std::ranges::replace(s, from, to);
    return s;
}

auto starts_with(const std::string& text, const std::string& prefix) -> bool {
    // Since C++20 you can use std::string::starts_with, but anyways.
    if (text.size() < prefix.size()) return false;
    // uz -> unsigned size_t
    for (auto idx = 0uz; idx < prefix.size(); ++idx) {
        if (text[idx] != prefix[idx]) return false;
    }
    return true;
}

}  // namespace arrays