to_static_string and to_static_wstring overloads

2025-07-29 20:17:35 +02:00 · 2019-12-20 02:34:04 -05:00
parent c83e21e8f2
commit 4e4dcce1f1
3 changed files with 352 additions and 104 deletions
--- a/include/boost/static_string/detail/static_string.hpp
+++ b/include/boost/static_string/detail/static_string.hpp
@ -15,14 +15,22 @@
 #include <iterator>
 #include <type_traits>
 #include <limits>
+#include <cwchar>

 namespace boost {
 namespace static_string {
-namespace detail {

 template<std::size_t, typename, typename>
 class basic_static_string;

+namespace detail {
+
+template<std::size_t N>
+using static_string = basic_static_string<N, char, std::char_traits<char>>;
+
+template<std::size_t N>
+using static_wstring = basic_static_string<N, wchar_t, std::char_traits<wchar_t>>;
+
 // At minimum an integral type shall not qualify as an iterator (Agustin Berge)
 template<class T>
 using is_input_iterator =
@ -288,73 +296,128 @@ lexicographical_compare(
    s1.data(), s1.size(), s2.data(), s2.size());
 }

-// Maximum number of characters in the decimal
-// representation of a binary number. This includes
-// the potential minus sign.
-//
-BOOST_STATIC_STRING_CPP11_CONSTEXPR
+template<typename Traits, typename Integer>
 inline
-std::size_t
-max_digits(std::size_t bytes)
+char*
+integer_to_string(
+    char* str_end, Integer value, std::true_type)
 {
-    return static_cast<std::size_t>(
-        bytes * 2.41) + 1 + 1;
+    if (value == 0)
+    {
+      Traits::assign(*--str_end, '0');
+      return str_end;
+    }
+    if (value < 0)
+    {
+        value = -value;
+        for(; value > 0; value /= 10)
+            Traits::assign(*--str_end, "0123456789"[value % 10]);
+        Traits::assign(*--str_end, '-');
+        return str_end;
+    }
+    for (; value > 0; value /= 10)
+        Traits::assign(*--str_end, "0123456789"[value % 10]);
+    return str_end;
 }

-template<typename CharT, class Integer, typename Traits>
+template<typename Traits, typename Integer>
 inline
-CharT*
-raw_to_string(
-    CharT* buf, Integer x, std::true_type)
+char*
+integer_to_string(
+    char* str_end, Integer value, std::false_type)
 {
-    if(x == 0)
+    if (value == 0)
    {
-        Traits::assign(*--buf, '0');
-        return buf;
+      Traits::assign(*--str_end, '0');
+      return str_end;
    }
-    if(x < 0)
-    {
-        x = -x;
-        for(;x > 0; x /= 10)
-            Traits::assign(*--buf ,
-                "0123456789"[x % 10]);
-        Traits::assign(*--buf, '-');
-        return buf;
-    }
-    for(;x > 0; x /= 10)
-        Traits::assign(*--buf ,
-            "0123456789"[x % 10]);
-    return buf;
+    for (; value > 0; value /= 10)
+        Traits::assign(*--str_end, "0123456789"[value % 10]);
+    return str_end;
 }

-template<typename CharT, class Integer, typename Traits>
+template<typename Traits, typename Integer>
 inline
-CharT*
-raw_to_string(
-    CharT* buf, Integer x, std::false_type)
+wchar_t*
+integer_to_wstring(
+  wchar_t* str_end, Integer value, std::true_type)
 {
-    if(x == 0)
-    {
-        *--buf = '0';
-        return buf;
-    }
-    for(;x > 0; x /= 10)
-        Traits::assign(*--buf ,
-            "0123456789"[x % 10]);
-    return buf;
+  if (value == 0)
+  {
+    Traits::assign(*--str_end, L'0');
+    return str_end;
+  }
+  if (value < 0)
+  {
+    value = -value;
+    for (; value > 0; value /= 10)
+      Traits::assign(*--str_end, L"0123456789"[value % 10]);
+    Traits::assign(*--str_end, L'-');
+    return str_end;
+  }
+  for (; value > 0; value /= 10)
+    Traits::assign(*--str_end, L"0123456789"[value % 10]);
+  return str_end;
 }

-template<
-    typename CharT,
-    class Integer,
-    typename Traits = std::char_traits<CharT>>
+template<typename Traits, typename Integer>
 inline
-CharT*
-raw_to_string(CharT* last, std::size_t size, Integer i)
+wchar_t*
+integer_to_wstring(
+  wchar_t* str_end, Integer value, std::false_type)
 {
-    BOOST_STATIC_STRING_ASSERT(size >= max_digits(sizeof(Integer)));
-    return raw_to_string<CharT, Integer, Traits>(
-        last, i, std::is_signed<Integer>{});
+  if (value == 0)
+  {
+    Traits::assign(*--str_end, L'0');
+    return str_end;
+  }
+  for (; value > 0; value /= 10)
+    Traits::assign(*--str_end, L"0123456789"[value % 10]);
+  return str_end;
+}
+
+template<typename Traits, std::size_t N, typename Integer>
+inline
+static_string<N>
+to_static_string_int_impl(Integer value)
+{
+  char buffer[N];
+  const auto digits_end = std::end(buffer);
+  const auto digits_begin = integer_to_string<Traits, Integer>(
+    digits_end, value, std::is_signed<Integer>{});
+  return static_string<N>(digits_begin, std::distance(digits_begin, digits_end));
+}
+
+template<typename Traits, std::size_t N, typename Integer>
+inline
+static_wstring<N>
+to_static_wstring_int_impl(Integer value)
+{
+  wchar_t buffer[N];
+  const auto digits_end = std::end(buffer);
+  const auto digits_begin = integer_to_wstring<Traits, Integer>(
+    digits_end, value, std::is_signed<Integer>{});
+  return static_wstring<N>(digits_begin, std::distance(digits_begin, digits_end));
+}
+
+template<std::size_t N, typename Floating>
+inline
+static_string<N>
+to_static_string_float_impl(Floating value)
+{
+  char buffer[N];
+  std::sprintf(buffer, "%f", value);
+  return static_string<N>(buffer);
+}
+
+template<std::size_t N, typename Floating>
+inline
+static_wstring<N>
+to_static_wstring_float_impl(Floating value)
+{
+  wchar_t buffer[N];
+  std::swprintf(buffer, L"%f", value);
+  return static_wstring<N>(buffer);
 }

 template<
--- a/include/boost/static_string/impl/static_string.hpp
+++ b/include/boost/static_string/impl/static_string.hpp
@ -836,24 +836,152 @@ assign_char(CharT, std::false_type) ->
    return *this;
 }

-template<class Integer, class>
+// string
+
+static_string<std::numeric_limits<int>::digits10 + 1>
 inline
-basic_static_string<detail::max_digits(sizeof(Integer)), char>
-to_static_string(Integer x)
+to_static_string(int value)
 {
-    using CharT = char;
-    using Traits = std::char_traits<CharT>;
-    BOOST_STATIC_STRING_STATIC_ASSERT(std::is_integral<Integer>::value, "Integer must be an integral type");
-    char buf[detail::max_digits(sizeof(Integer))];
-    auto last = buf + sizeof(buf);
-    auto it = detail::raw_to_string<
-        CharT, Integer, Traits>(last, sizeof(buf), x);
-    basic_static_string<detail::max_digits(sizeof(Integer)), char> s;
-    s.resize(static_cast<std::size_t>(last - it));
-    auto p = s.data();
-    while(it < last)
-        Traits::assign(*p++, *it++);
-    return s;
+  return detail::to_static_string_int_impl<
+    std::char_traits<char>, std::numeric_limits<int>::digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<long>::digits10 + 1>
+inline
+to_static_string(long value)
+{
+  return detail::to_static_string_int_impl<
+    std::char_traits<char>, std::numeric_limits<long>::digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<long long>::digits10 + 1>
+inline
+to_static_string(long long value)
+{
+  return detail::to_static_string_int_impl<
+    std::char_traits<char>, std::numeric_limits<long long>::digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<unsigned int>::digits10 + 1>
+inline
+to_static_string(unsigned int value)
+{
+  return detail::to_static_string_int_impl<
+    std::char_traits<char>, std::numeric_limits<unsigned int>::digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<unsigned long>::digits10 + 1>
+inline
+to_static_string(unsigned long value)
+{
+  return detail::to_static_string_int_impl<
+    std::char_traits<char>, std::numeric_limits<unsigned long>::digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<unsigned long long>::digits10 + 1>
+inline
+to_static_string(unsigned long long value)
+{
+  return detail::to_static_string_int_impl<
+    std::char_traits<char>, std::numeric_limits<unsigned long long>::digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<float>::max_digits10 + 1>
+inline
+to_static_string(float value)
+{
+  return detail::to_static_string_float_impl<
+    std::numeric_limits<float>::max_digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<double>::max_digits10 + 1>
+inline
+to_static_string(double value)
+{
+  return detail::to_static_string_float_impl<
+    std::numeric_limits<double>::max_digits10 + 1>(value);
+}
+
+static_string<std::numeric_limits<long double>::max_digits10 + 1>
+inline
+to_static_string(long double value)
+{
+  return detail::to_static_string_float_impl<
+    std::numeric_limits<long double>::max_digits10 + 1>(value);
+}
+
+// wstring
+
+static_wstring<std::numeric_limits<int>::digits10 + 1>
+inline
+to_static_wstring(int value)
+{
+  return detail::to_static_wstring_int_impl<
+    std::char_traits<wchar_t>, std::numeric_limits<int>::digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<long>::digits10 + 1>
+inline
+to_static_wstring(long value)
+{
+  return detail::to_static_wstring_int_impl<
+    std::char_traits<wchar_t>, std::numeric_limits<long>::digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<long long>::digits10 + 1>
+inline
+to_static_wstring(long long value)
+{
+  return detail::to_static_wstring_int_impl<
+    std::char_traits<wchar_t>, std::numeric_limits<long long>::digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<unsigned int>::digits10 + 1>
+inline
+to_static_wstring(unsigned int value)
+{
+  return detail::to_static_wstring_int_impl<
+    std::char_traits<wchar_t>, std::numeric_limits<unsigned int>::digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<unsigned long>::digits10 + 1>
+inline
+to_static_wstring(unsigned long value)
+{
+  return detail::to_static_wstring_int_impl<
+    std::char_traits<wchar_t>, std::numeric_limits<unsigned long>::digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<unsigned long long>::digits10 + 1>
+inline
+to_static_wstring(unsigned long long value)
+{
+  return detail::to_static_wstring_int_impl<
+    std::char_traits<wchar_t>, std::numeric_limits<unsigned long long>::digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<float>::max_digits10 + 1>
+inline
+to_static_wstring(float value)
+{
+  return detail::to_static_wstring_float_impl<
+    std::numeric_limits<float>::max_digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<double>::max_digits10 + 1>
+inline
+to_static_wstring(double value)
+{
+  return detail::to_static_wstring_float_impl<
+    std::numeric_limits<double>::max_digits10 + 1>(value);
+}
+
+static_wstring<std::numeric_limits<long double>::max_digits10 + 1>
+inline
+to_static_wstring(long double value)
+{
+  return detail::to_static_wstring_float_impl<
+    std::numeric_limits<long double>::max_digits10 + 1>(value);
 }

 } // static_string
--- a/include/boost/static_string/static_string.hpp
+++ b/include/boost/static_string/static_string.hpp
@ -2773,31 +2773,105 @@ operator<<(std::basic_ostream<CharT, Traits>& os,
    return os << basic_string_view<CharT, Traits>(s.data(), s.size());
 }

+//------------------------------------------------------------------------------
+//
+// Aliases
+//
+//------------------------------------------------------------------------------
+
+template<std::size_t N>
+using static_string = basic_static_string<N, char>;
+
+template<std::size_t N>
+using static_wstring = basic_static_string<N, wchar_t>;
+
+template<std::size_t N>
+using static_u16string = basic_static_string<N, char16_t>;
+
+template<std::size_t N>
+using static_u32string = basic_static_string<N, char32_t>;
+
 //------------------------------------------------------------------------------
 //
 // Numeric conversions
 //
 //------------------------------------------------------------------------------

-/** Returns a static string representing an integer as a decimal.
+// string

-    @param x The signed or unsigned integer to convert.
-    This must be an integral type.
-
-    @return A @ref basic_static_string with an implementation defined
-    maximum size at least as large enough to hold the longest
-    possible decimal representation of any integer of the given type.
-*/
-template<
-    class Integer
-#ifndef GENERATING_DOCUMENTATION
-    , class = typename std::enable_if<
-        std::is_integral<Integer>::value>::type
-#endif
->
+static_string<std::numeric_limits<int>::digits10 + 1>
 inline
-basic_static_string<detail::max_digits(sizeof(Integer)), char>
-to_static_string(Integer x);
+to_static_string(int value);
+
+static_string<std::numeric_limits<long>::digits10 + 1>
+inline
+to_static_string(long value);
+
+static_string<std::numeric_limits<long long>::digits10 + 1>
+inline
+to_static_string(long long value);
+
+static_string<std::numeric_limits<unsigned int>::digits10 + 1>
+inline
+to_static_string(unsigned int value);
+
+static_string<std::numeric_limits<unsigned long>::digits10 + 1>
+inline
+to_static_string(unsigned long value);
+
+static_string<std::numeric_limits<unsigned long long>::digits10 + 1>
+inline
+to_static_string(unsigned long long value);
+
+static_string<std::numeric_limits<float>::max_digits10 + 1>
+inline
+to_static_string(float value);
+
+static_string<std::numeric_limits<double>::max_digits10 + 1>
+inline
+to_static_string(double value);
+
+static_string<std::numeric_limits<long double>::max_digits10 + 1>
+inline
+to_static_string(long double value);
+
+// wstring
+
+static_wstring<std::numeric_limits<int>::digits10 + 1>
+inline
+to_static_wstring(int value);
+
+static_wstring<std::numeric_limits<long>::digits10 + 1>
+inline
+to_static_wstring(long value);
+
+static_wstring<std::numeric_limits<long long>::digits10 + 1>
+inline
+to_static_wstring(long long value);
+
+static_wstring<std::numeric_limits<unsigned int>::digits10 + 1>
+inline
+to_static_wstring(unsigned int value);
+
+static_wstring<std::numeric_limits<unsigned long>::digits10 + 1>
+inline
+to_static_wstring(unsigned long value);
+
+static_wstring<std::numeric_limits<unsigned long long>::digits10 + 1>
+inline
+to_static_wstring(unsigned long long value);
+
+static_wstring<std::numeric_limits<float>::max_digits10 + 1>
+inline
+to_static_wstring(float value);
+
+static_wstring<std::numeric_limits<double>::max_digits10 + 1>
+inline
+to_static_wstring(double value);
+
+static_wstring<std::numeric_limits<long double>::max_digits10 + 1>
+inline
+to_static_wstring(long double value);

 //------------------------------------------------------------------------------
 //
@ -2829,29 +2903,12 @@ hash_value(
    return boost::hash_range(str.begin(), str.end());
 }
 #endif
-
-//------------------------------------------------------------------------------
-//
-// Aliases
-//
-//------------------------------------------------------------------------------
-
-template<std::size_t N>
-using static_string = basic_static_string<N, char>;
-
-template<std::size_t N>
-using static_wstring = basic_static_string<N, wchar_t>;
-
-template<std::size_t N>
-using static_u16string = basic_static_string<N, char16_t>;
-
-template<std::size_t N>
-using static_u32string = basic_static_string<N, char32_t>;
-
 } // static_string
 } // boost

+#ifndef GENERATING_DOCUMENTATION
 // std::hash partial specialization for basic_static_string
+#endif
 namespace std
 {
  template <std::size_t N, typename CharT, typename Traits>