update iguana and cfg

include/iguana/define.h

@@ -0,0 +1,101 @@
+#pragma once
+
+#include <array>
+#include <bit>
+#include <string>
+#include <string_view>
+#include <type_traits>
+#include <vector>
+
+#if defined __clang__
+#define IGUANA_INLINE __attribute__((always_inline)) inline
+#define IGUANA__INLINE_LAMBDA __attribute__((always_inline)) constexpr
+#elif defined _MSC_VER
+#define IGUANA_INLINE __forceinline
+#define IGUANA__INLINE_LAMBDA constexpr
+#else
+#define IGUANA_INLINE __attribute__((always_inline)) inline
+#define IGUANA__INLINE_LAMBDA constexpr __attribute__((always_inline))
+#endif
+
+#if __has_cpp_attribute(likely) && __has_cpp_attribute(unlikely)
+#define IGUANA_LIKELY [[likely]]
+#define IGUANA_UNLIKELY [[unlikely]]
+#else
+#define IGUANA_LIKELY
+#define IGUANA_UNLIKELY
+#endif
+
+#ifdef _MSC_VER
+
+#if _MSC_VER >= 1920 && _MSVC_LANG >= 202002L
+IGUANA_INLINE int countr_zero(unsigned long long x) {
+  return std::countr_zero(x);
+}
+template <typename T>
+constexpr inline bool contiguous_iterator = std::contiguous_iterator<T>;
+
+#else
+IGUANA_INLINE int countr_zero(unsigned long long x) {
+  // x will never be zero in iguana
+  unsigned long pos;
+  _BitScanForward64(&pos, x);
+  return pos;
+}
+
+namespace std {
+template <typename T>
+using remove_cvref_t =
+    typename remove_cv<typename remove_reference<T>::type>::type;
+}
+template <typename T>
+constexpr inline bool contiguous_iterator =
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::vector<char>::iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::vector<char>::const_iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>, typename std::string::iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::string::const_iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>, char *> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::string_view::iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::string_view::const_iterator>;
+#endif
+
+#else
+
+#if __cplusplus >= 202002L
+IGUANA_INLINE int countr_zero(unsigned long long x) {
+  return std::countr_zero(x);
+}
+template <typename T>
+constexpr inline bool contiguous_iterator = std::contiguous_iterator<T>;
+#else
+IGUANA_INLINE int countr_zero(unsigned long long x) {
+  // x will never be zero in iguana
+  return __builtin_ctzll(x);
+}
+namespace std {
+template <typename T>
+using remove_cvref_t =
+    typename remove_cv<typename remove_reference<T>::type>::type;
+}
+template <typename T>
+constexpr inline bool contiguous_iterator =
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::vector<char>::iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::vector<char>::const_iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>, typename std::string::iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::string::const_iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>, char *> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::string_view::iterator> ||
+    std::is_same_v<std::remove_cvref_t<T>,
+                   typename std::string_view::const_iterator>;
+#endif
+
+#endif

include/iguana/detail/charconv.h

@@ -0,0 +1,45 @@
+#pragma once
+#include "dragonbox_to_chars.h"
+#include "fast_float.h"
+#include "itoa.hpp"
+#include <charconv>
+
+namespace iguana {
+template <typename T>
+struct is_char_type
+    : std::disjunction<std::is_same<T, char>, std::is_same<T, unsigned char>,
+                       std::is_same<T, signed char>, std::is_same<T, wchar_t>,
+                       std::is_same<T, char16_t>, std::is_same<T, char32_t>> {};
+
+namespace detail {
+template <typename U>
+std::pair<const char *, std::errc>
+from_chars(const char *first, const char *last, U &value) noexcept {
+  using T = std::decay_t<U>;
+  if constexpr (std::is_floating_point_v<T>) {
+    auto [p, ec] = fast_float::from_chars(first, last, value);
+    return {p, ec};
+  } else {
+    auto [p, ec] = std::from_chars(first, last, value);
+    return {p, ec};
+  }
+}
+
+// not support uint8 for now
+template <typename T> char *to_chars(char *buffer, T value) noexcept {
+  using U = std::decay_t<T>;
+  if constexpr (std::is_floating_point_v<U>) {
+    return jkj::dragonbox::to_chars(value, buffer);
+  } else if constexpr (std::is_signed_v<U> && (sizeof(U) >= 8)) {
+    return xtoa(value, buffer, 10, 1); // int64_t
+  } else if constexpr (std::is_unsigned_v<U> && (sizeof(U) >= 8)) {
+    return xtoa(value, buffer, 10, 0); // uint64_t
+  } else if constexpr (std::is_integral_v<U> && !is_char_type<U>::value) {
+    return itoa_fwd(value, buffer); // only support more than 2 bytes intergal
+  } else {
+    static_assert(!sizeof(U), "only support arithmetic type except char type");
+  }
+}
+
+} // namespace detail
+} // namespace iguana