Use inline constexpr for some arrays

Author: Morwenn

docs/Changelog.md

@@ -36,11 +36,6 @@ When compiled with C++17, **cpp-sort** might gain a few additional features depe
 
     There is no specific feature macro available to test this, it starts working when `std::begin` and `std::end` are `constexpr`.
 
-**Size improvements:**
-* When used in different translation units, [`smooth_sorter`][smooth-sorter] might produce fewer duplicates and consume less binary size in C++17.
-
-    This optimization is available when the feature-testing macro `__cpp_inline_variables` is available.
-
 ## C++20 features
 
 When compiled with C++20, **cpp-sort** might gain a few additional features depending on the level of C++20 support provided by the compiler. The availability of those features depends on the presence of corresponding [feature-testing macros][feature-test-macros] when possible, even though some checks are more granular. Don't hesitate to open an issue if your compiler and standard library supports one of those features but it doesn't seem to work in **cpp-sort**.
@@ -78,7 +73,6 @@ When compiled with C++20, **cpp-sort** might gain a few additional features depe
   [feature-test-macros]: https://wg21.link/SD6
   [pdq-sorter]: Sorters.md#pdq_sorter
   [ska-sorter]: Sorters.md#ska_sorter
-  [smooth-sorter]: Sorters.md#smooth-sorter_sorter
   [sorter-facade]: Sorter-facade.md
   [std-greater-void]: https://en.cppreference.com/w/cpp/utility/functional/greater_void
   [std-identity]: https://en.cppreference.com/w/cpp/utility/functional/identity

include/cpp-sort/detail/config.h

@@ -27,18 +27,6 @@
 #   define __has_cpp_attribute(x) 0
 #endif
 
-////////////////////////////////////////////////////////////
-// Check for C++17 features
-
-// Make sure that there is a single variable before C++17,
-// default to static in C++14 to avoid ODR issues
-
-#if defined(__cpp_inline_variables)
-#   define CPPSORT_INLINE_VARIABLE inline
-#else
-#   define CPPSORT_INLINE_VARIABLE static
-#endif
-
 ////////////////////////////////////////////////////////////
 // Check for C++20 features
 

include/cpp-sort/detail/smoothsort.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2021 Morwenn
+ * Copyright (c) 2015-2025 Morwenn
  * SPDX-License-Identifier: MIT
  */
 
@@ -38,12 +38,12 @@ namespace detail
       /* A constant containing the number of Leonardo numbers that can fit into
        * 64 bits.
        */
-      CPPSORT_INLINE_VARIABLE constexpr std::size_t kNumLeonardoNumbers = 92;
+      inline constexpr std::size_t kNumLeonardoNumbers = 92;
 
       /* A list of all the Leonardo numbers below 2^64, precomputed for
        * efficiency.
        */
-      CPPSORT_INLINE_VARIABLE constexpr std::uint_fast64_t kLeonardoNumbers[kNumLeonardoNumbers] = {
+      inline constexpr std::uint_fast64_t kLeonardoNumbers[kNumLeonardoNumbers] = {
         1u, 1u, 3u, 5u, 9u, 15u, 25u, 41u, 67u, 109u, 177u, 287u, 465u, 753u,
         1219u, 1973u, 3193u, 5167u, 8361u, 13529u, 21891u, 35421u, 57313u,
         92735u, 150049u, 242785u, 392835u, 635621u, 1028457u, 1664079u,