charconv.h

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#pragma once

// FastLED Character Conversion Functions (charconv.h equivalents)
//
// Provides character/string conversion utilities similar to C++17 <charconv>
// but adapted for embedded platforms and FastLED's needs.
//
// All functions are in the fl:: namespace.
 
#include "fl/stl/stdint.h"  // For u64, uint8_t
#include "fl/stl/cstddef.h" // For fl::size_t
#include "fl/stl/noexcept.h"
#include "fl/stl/static_assert.h"
 
namespace fl {
 
// Forward declaration to avoid circular dependency
class string;

template<typename T>
fl::string to_hex(T value, bool uppercase = false, bool pad_to_width = false) FL_NOEXCEPT;
 
namespace detail {

enum class HexIntWidth : u8 {
    Width8 = 8,
    Width16 = 16,
    Width32 = 32,
    Width64 = 64
};

fl::string hex(u64 value, HexIntWidth width, bool is_negative, bool uppercase, bool pad_to_width) FL_NOEXCEPT;

template<size_t Size>
constexpr HexIntWidth get_hex_int_width() FL_NOEXCEPT {
    FL_STATIC_ASSERT(Size == 0, "Unsupported type size for hex conversion");
    return HexIntWidth::Width8; // Unreachable, but needed for compilation
}

template<>
constexpr HexIntWidth get_hex_int_width<1>() FL_NOEXCEPT {
    return HexIntWidth::Width8;
}

template<>
constexpr HexIntWidth get_hex_int_width<2>() FL_NOEXCEPT {
    return HexIntWidth::Width16;
}

template<>
constexpr HexIntWidth get_hex_int_width<4>() FL_NOEXCEPT {
    return HexIntWidth::Width32;
}

template<>
constexpr HexIntWidth get_hex_int_width<8>() FL_NOEXCEPT {
    return HexIntWidth::Width64;
}
 
} // namespace detail
 
// Low-level integer to string conversion functions
// These provide the foundational conversion logic for fl::string and fl::sstream

int itoa(i32 value, char *buffer, int radix) FL_NOEXCEPT;

int itoa64(i64 value, char *buffer, int radix) FL_NOEXCEPT;

int utoa32(u32 value, char *buffer, int radix) FL_NOEXCEPT;

int utoa64(u64 value, char *buffer, int radix) FL_NOEXCEPT;

void ftoa(float value, char *buffer, int precision = 2) FL_NOEXCEPT;

float parseFloat(const char *str, fl::size len) FL_NOEXCEPT;

int parseInt(const char *str, fl::size len) FL_NOEXCEPT;

int parseInt(const char *str) FL_NOEXCEPT;
 
} // namespace fl

// Template Implementation Section
//
// NOTE: The template implementation for to_hex<T>() is defined at the END of
// fl/stl/string.h (after the fl::string class definition is complete).
// This avoids circular dependency issues where charconv.h is included by
// string.h before the string class is fully defined.