Unconditional support for std::[w]string_view (#66)

Author: Morwenn

docs/Changelog.md

@@ -12,10 +12,6 @@ While **cpp-sort** theoretically requires a fully C++17-compliant compiler, a fe
 When compiled with C++17, **cpp-sort** might gain a few additional features depending on the level of C++17 support provided by the compiler. The availability of most of the features depends on the presence of corresponding [feature-testing macros][feature-test-macros]. The support for feature-testing macros being optional in C++17, it is possible that some of the features listed below aren't available even though the compiler is implements them. If it is the case and it is a problem for you, don't hesitate to open an issue so that we can explicitly support the given compiler.
 
 **New features:**
-* `string_spread_sort` now accepts [`std::string_view`][std-string-view] and sometimes `std::wstring_view`.
-
-    This feature is made available through the check `__cplusplus > 201402L && __has_include(<string_view>)`.
-
 * Sorter adapters have been updated to take advantage of deduction guides:
 
     ```cpp
@@ -100,6 +96,5 @@ When compiled with C++20, **cpp-sort** might gain a few additional features depe
   [std-mem-fn]: https://en.cppreference.com/w/cpp/utility/functional/mem_fn
   [std-ranges-greater]: https://en.cppreference.com/w/cpp/utility/functional/ranges/greater
   [std-ranges-less]: https://en.cppreference.com/w/cpp/utility/functional/ranges/less
-  [std-string-view]: https://en.cppreference.com/w/cpp/string/basic_string_view
   [std-swap]: https://en.cppreference.com/w/cpp/algorithm/swap
   [utility-iter-move]: Miscellaneous-utilities.md#iter_move-and-iter_swap

docs/Sorters.md

@@ -593,7 +593,7 @@ It comes into three main flavours (available individually if needed):
 
 * `integer_spread_sorter` works with any type satisfying the trait `std::is_integral`.
 * `float_spread_sorter` works with any type satisfying the trait `std::numeric_limits::is_iec559` whose size is the same as `std::uint32_t` or `std::uin64_t`.
-* `string_spread_sorter` works with `std::string` and `std::wstring` (if `wchar_t` is 2 bytes). This sorter also supports reverse sorting with `std::greater<>` and `std::ranges::greater`. In C++17 it also works with `std::string_view` and `std::wstring_view` (if `wchar_t` is 2 bytes).
+* `string_spread_sorter` works with `std::string` and `std::string_view`, as well as `std::wstring` and `std::wstring_view` when `wchar_t` is 2 bytes. This sorter also supports reverse sorting with `std::greater<>` and `std::ranges::greater`.
 
 These sorters accept projections as long as their simplest form can handle the result of the projection. The three of them are aggregated into one main sorter the following way:
 

include/cpp-sort/sorters/spread_sorter/string_spread_sorter.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2021 Morwenn
+ * Copyright (c) 2015-2025 Morwenn
  * SPDX-License-Identifier: MIT
  */
 #ifndef CPPSORT_SORTERS_SPREAD_SORTER_STRING_SPREAD_SORTER_H_
@@ -12,6 +12,7 @@
 #include <functional>
 #include <iterator>
 #include <string>
+#include <string_view>
 #include <type_traits>
 #include <utility>
 #include <cpp-sort/sorter_facade.h>
@@ -22,10 +23,6 @@
 #include "../../detail/spreadsort/string_sort.h"
 #include "../../detail/type_traits.h"
 
-#if __cplusplus > 201402L && __has_include(<string_view>)
-#   include <string_view>
-#endif
-
 namespace cppsort
 {
     ////////////////////////////////////////////////////////////
@@ -46,9 +43,7 @@ namespace cppsort
                             Projection projection={}) const
                 -> detail::enable_if_t<
                     std::is_same<projected_t<RandomAccessIterator, Projection>, std::string>::value
-#if __cplusplus > 201402L && __has_include(<string_view>)
                     || std::is_same<projected_t<RandomAccessIterator, Projection>, std::string_view>::value
-#endif
                 >
             {
                 static_assert(
@@ -72,9 +67,7 @@ namespace cppsort
                             Projection projection={}) const
                 -> detail::enable_if_t<(
                         std::is_same<projected_t<RandomAccessIterator, Projection>, std::wstring>::value
-#if __cplusplus > 201402L && __has_include(<string_view>)
                         || std::is_same<projected_t<RandomAccessIterator, Projection>, std::wstring_view>::value
-#endif
                     ) && (sizeof(wchar_t) == 2)
                 >
             {
@@ -102,9 +95,7 @@ namespace cppsort
                             std::greater<> compare, Projection projection={}) const
                 -> detail::enable_if_t<
                     std::is_same<projected_t<RandomAccessIterator, Projection>, std::string>::value
-#if __cplusplus > 201402L && __has_include(<string_view>)
                     || std::is_same<projected_t<RandomAccessIterator, Projection>, std::string_view>::value
-#endif
                 >
             {
                 static_assert(
@@ -129,9 +120,7 @@ namespace cppsort
                             std::greater<> compare, Projection projection={}) const
                 -> detail::enable_if_t<(
                         std::is_same<projected_t<RandomAccessIterator, Projection>, std::wstring>::value
-#if __cplusplus > 201402L && __has_include(<string_view>)
                         || std::is_same<projected_t<RandomAccessIterator, Projection>, std::wstring_view>::value
-#endif
                     ) && (sizeof(wchar_t) == 2)
                 >
             {