string_view.hpp

#ifndef MSTL_CORE_STRING_STRING_VIEW_HPP__
#define MSTL_CORE_STRING_STRING_VIEW_HPP__
#include "basic_string_view.hpp"
MSTL_BEGIN_NAMESPACE__
 
using string_view    = basic_string_view<char>;
using bstring_view   = basic_string_view<byte_t>;
using wstring_view   = basic_string_view<wchar_t>;
#ifdef MSTL_STANDARD_20__
using u8string_view  = basic_string_view<char8_t>;
#endif // MSTL_STANDARD_20__
using u16string_view = basic_string_view<char16_t>;
using u32string_view = basic_string_view<char32_t>;
 
 
MSTL_BEGIN_LITERALS__
MSTL_NODISCARD constexpr string_view operator ""_sv(const char* str, size_t len) noexcept {
    return {str, len};
}
MSTL_NODISCARD constexpr wstring_view operator ""_sv(const wchar_t* str, size_t len) noexcept {
    return {str, len};
}
#ifdef MSTL_STANDARD_20__
MSTL_NODISCARD constexpr u8string_view operator ""_sv(const char8_t* str, size_t len) noexcept {
    return {str, len};
}
#endif // MSTL_STANDARD_20__
MSTL_NODISCARD constexpr u16string_view operator ""_sv(const char16_t* str, size_t len) noexcept {
    return {str, len};
}
MSTL_NODISCARD constexpr u32string_view operator ""_sv(const char32_t* str, size_t len) noexcept {
    return {str, len};
}
MSTL_END_LITERALS__
 
 
template <typename CharT>
constexpr bool getline(const basic_string_view<CharT> data, size_t& pos,
    basic_string_view<CharT>& str, CharT delim = static_cast<CharT>('\n')) {
 
    if (pos >= data.size()) {
        str = basic_string_view<CharT>();
        return false;
    }
 
    size_t start = pos;
    size_t end = pos;
    while (end < data.size() && data[end] != delim) {
        ++end;
    }
    str = data.substr(start, end - start);
    pos = (end < data.size()) ? end + 1 : end;
 
    return true;
}
 
template <typename CharT, typename Pred>
constexpr bool getline(const basic_string_view<CharT> data, size_t& pos,
    basic_string_view<CharT>& str, Pred split = [](const CharT ch) {
        return ch == static_cast<CharT>('\n');
    }) {
 
    if (pos >= data.size()) {
        str = basic_string_view<CharT>();
        return false;
    }
 
    size_t start = pos;
    size_t end = pos;
    while (end < data.size() && !split(data[end])) {
        ++end;
    }
    str = data.substr(start, end - start);
    pos = (end < data.size()) ? end + 1 : end;
 
    return true;
}
 
MSTL_END_NAMESPACE__
#endif // MSTL_CORE_STRING_STRING_VIEW_HPP__