char formatters for utf string/views (#2)

include/stralgo/utf/detail/foramtters.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <stralgo/utf/utf.h>
+#include <format>
+#include <ranges>
+
+namespace stralgo::utf::detail
+  {
+template<typename input_range, typename output_iterator>
+inline auto tansform_to_conetxt(input_range const & str, output_iterator oit)
+  {
+  stralgo::utf::utf_input_view_t source{str};
+  stralgo::utf::utf_explicit_output_iterator_t<char>::iterator utf_oit{oit};
+  return std::ranges::copy(source, utf_oit).out.base();
+  }
+  }  // namespace stralgo::utf::detail
+
+namespace stralgo::concepts
+  {
+template<typename char_type>
+concept format_char_type
+  = std::same_as<char_type, wchar_t> or std::same_as<char_type, char16_t> or std::same_as<char_type, char32_t>;
+  }
+

include/stralgo/utf/foramtters/small_vectors/string.h

@@ -0,0 +1,24 @@
+#pragma once
+
+#include <stralgo/utf/utf.h>
+#include <stralgo/utf/detail/foramtters.h>
+#include <small_vectors/basic_string.h>
+#include <format>
+#include <ranges>
+
+template<stralgo::concepts::format_char_type char_type, uint64_t capacity, typename tag>
+struct std::formatter<small_vectors::basic_string_t<char_type, capacity, tag>, char>
+  {
+  template<typename ParseContext>
+  constexpr auto parse(ParseContext & ctx) -> decltype(ctx.begin())
+    {
+    return ctx.begin();
+    }
+
+  template<typename FormatContext>
+  auto format(small_vectors::basic_string_t<char_type, capacity, tag> const & str, FormatContext & ctx) const
+    -> decltype(ctx.out())
+    {
+    return stralgo::utf::detail::tansform_to_conetxt(str, ctx.out());
+    }
+  };

include/stralgo/utf/foramtters/std/string.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <stralgo/utf/utf.h>
+#include <stralgo/utf/detail/foramtters.h>
+#include <format>
+#include <ranges>
+
+template<stralgo::concepts::format_char_type char_type>
+struct std::formatter<std::basic_string<char_type>, char>
+  {
+  template<typename ParseContext>
+  constexpr auto parse(ParseContext & ctx) -> decltype(ctx.begin())
+    {
+    return ctx.begin();
+    }
+
+  template<typename FormatContext>
+  auto format(std::basic_string<char_type> const & str, FormatContext & ctx) const -> decltype(ctx.out())
+    {
+    return stralgo::utf::detail::tansform_to_conetxt(str, ctx.out());
+    }
+  };
+

include/stralgo/utf/foramtters/std/string_view.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include <stralgo/utf/utf.h>
+#include <stralgo/utf/detail/foramtters.h>
+#include <format>
+#include <ranges>
+
+template<stralgo::concepts::format_char_type char_type>
+struct std::formatter<std::basic_string_view<char_type>, char>
+  {
+  template<typename ParseContext>
+  constexpr auto parse(ParseContext & ctx) -> decltype(ctx.begin())
+    {
+    return ctx.begin();
+    }
+
+  template<typename FormatContext>
+  auto format(std::basic_string_view<char_type> str, FormatContext & ctx) const -> decltype(ctx.out())
+    {
+    return stralgo::utf::detail::tansform_to_conetxt(str, ctx.out());
+    }
+  };
+

include/stralgo/utf/utf.h

@@ -165,6 +165,8 @@ struct utf_output_iterator_t
 
   inline constexpr explicit utf_output_iterator_t(target_iterator src) noexcept : iter_{src} {}
 
+  inline constexpr auto base() const noexcept -> target_iterator { return iter_; }
+
   inline constexpr utf_output_iterator_t & operator=(std::same_as<char32_t> auto cp) noexcept
     {
     iter_ = detail::append(cp, iter_);
@@ -199,6 +201,8 @@ struct utf_explicit_output_iterator_t
 
     inline constexpr explicit iterator(target_iterator src) noexcept : iter_{src} {}
 
+    inline constexpr auto base() const noexcept -> target_iterator { return iter_; }
+
     inline constexpr iterator & operator=(std::same_as<char32_t> auto cp) noexcept
       {
       iter_ = detail::explicit_append<char_type>(cp, iter_);
@@ -215,6 +219,7 @@ struct utf_explicit_output_iterator_t
       return *this;
       }
     };
+
   template<std::output_iterator<char_type> TargetIter>
   iterator(TargetIter src) -> iterator<TargetIter>;
   };

unittests/utf_.cc

@@ -1,5 +1,8 @@
 #include <unit_test_core.h>
 #include <stralgo/utf/utf.h>
+#include <stralgo/utf/foramtters/std/string.h>
+#include <stralgo/utf/foramtters/std/string_view.h>
+#include <stralgo/utf/foramtters/small_vectors/string.h>
 #include <codecvt>
 #include <cstdint>
 
@@ -512,5 +515,31 @@ int main()
     result |= run_constexpr_test(fn_tmpl);
     result |= run_consteval_test(fn_tmpl);
   };
-  }
 
+  "formatters"_test = [&]
+  {
+    using namespace std::string_view_literals;
+    using namespace std::string_literals;
+    using boost::ut::expect;
+    using boost::ut::eq;
+      {
+      auto res{std::format(
+        "{}-{}-{}-גראַדזשאַווייטיד", U"𐂀𐂁𐂂𐂃𐂄𐂅𐂆𐂇𐂈𐂉𐂊𐂋𐂌𐂍𐂎𐂏𐂐𐂑𐂒𐂓𐂔𐂕𐂖𐂗"sv, u"бакалавра"sv, L"𐀀𐀁𐀂𐀃𐀄𐀅𐀆"sv, L"גראַדזשאַווייטיד"s
+      )};
+      expect(eq(res, "𐂀𐂁𐂂𐂃𐂄𐂅𐂆𐂇𐂈𐂉𐂊𐂋𐂌𐂍𐂎𐂏𐂐𐂑𐂒𐂓𐂔𐂕𐂖𐂗-бакалавра-𐀀𐀁𐀂𐀃𐀄𐀅𐀆-גראַדזשאַווייטיד"sv));
+      }
+      {
+      using namespace small_vectors;
+      auto res{std::format(
+        "{}-{}-{} {}-{}-{}",
+        small_vectors::u16string{u"бакалавра"sv},
+        small_vectors::u32string{U"томатами"sv},
+        small_vectors::wstring{L"бакалавра"sv},
+        small_vectors::static_u16string<16>{u"томатами"sv},
+        small_vectors::static_u32string<16>{U"бакалавра"sv},
+        small_vectors::static_wstring<16>{L"томатами"sv}
+      )};
+      expect(eq(res, "бакалавра-томатами-бакалавра томатами-бакалавра-томатами"sv));
+      }
+  };
+  }