Class string

src/fl/stl/string.h:193–445

`fl::string` extends `string_n ` with the composite-type formatter overloads (CRGB, vec2, span, vector, optional, …), the `substring()` / `trim()` family (returning `string` so callers chain naturally), and the static factory + comparison methods. The trampoline pattern is: fl::string -> fl::string_n -> fl::basic_string where only `basic_string` carries the real bytes

// where only `basic_string` carries the real bytes; the upper
// layers are thin wrappers that get folded out by the optimizer.
class string : public string_n<FASTLED_STR_INLINED_SIZE> {
  public:
    static constexpr fl::size npos = static_cast<fl::size>(-1);

    using basic_string::copy;
    using basic_string::assign;
    using basic_string::append;
    using basic_string::appendHex;
    using basic_string::appendOct;

    // ======= STATIC FACTORY METHODS =======
    static string from_literal(const char* literal) FL_NOEXCEPT;
    static string from_view(const char* data, fl::size len) FL_NOEXCEPT;
    static string from_view(const string_view& sv) FL_NOEXCEPT;
    static string interned(const char* str, fl::size len) FL_NOEXCEPT;
    static string interned(const char* str) FL_NOEXCEPT;
    static string interned(const string_view& sv) FL_NOEXCEPT;
    static string copy_no_view(const string& str) FL_NOEXCEPT;
    static int strcmp(const string& a, const string& b) FL_NOEXCEPT;

    // ======= CONSTRUCTORS =======
    // All non-template ctors delegate to string_n<N>'s ctors —
    // defined in string.cpp.hpp as one-line forwarders for header
    // hygiene. Template ctors stay inline (they're parameterised
    // on caller types and can't be split out).
    string() FL_NOEXCEPT;
    string(const char* str) FL_NOEXCEPT;
    string(const char* str, fl::size len) FL_NOEXCEPT;
    string(fl::size len, char c) FL_NOEXCEPT;
    string(const string& other) FL_NOEXCEPT;
    string(string&& other) FL_NOEXCEPT;
    string(const basic_string& other) FL_NOEXCEPT;
    string(const string_view& sv) FL_NOEXCEPT;
    string(const fl::span<const char>& s) FL_NOEXCEPT;
    string(const fl::span<char>& s) FL_NOEXCEPT;
    string(const fl::shared_ptr<StringHolder>& holder) FL_NOEXCEPT;
    template <typename InputIt>
    string(InputIt first, InputIt last) FL_NOEXCEPT
        : string_n<FASTLED_STR_INLINED_SIZE>(first, last) {}
    template <int N>
    string(const char (&str)[N]) FL_NOEXCEPT
        : string_n<FASTLED_STR_INLINED_SIZE>(str) {}

    // ======= ASSIGNMENT =======
    string& operator=(const string& other) FL_NOEXCEPT;
    string& operator=(string&& other) FL_NOEXCEPT;
    string& operator=(const char* str) FL_NOEXCEPT;
    template <int N> string& operator=(const char (&str)[N]) FL_NOEXCEPT {
        assign(str, N - 1);
        return *this;
    }

    string& assign(string_view sv) FL_NOEXCEPT;

    // ======= SUBSTRING (returns string, so must live here) =======
    string substring(fl::size start, fl::size end) const FL_NOEXCEPT;
    string substr(fl::size start, fl::size length) const FL_NOEXCEPT;
    string substr(fl::size start) const FL_NOEXCEPT;