fix(buffer): make span_buffer compile with GCC < 13 during constant e…

…valuation (#89)

Fixes #88

cmake/dev-mode.cmake

@@ -43,9 +43,10 @@ endif ()
 
 
 if (BUILD_TESTING)
+    add_subdirectory(test/benchmark)
+    add_subdirectory(test/compile_test)
     add_subdirectory(test/static_analysis)
     add_subdirectory(test/unit_test)
-    add_subdirectory(test/benchmark)
 endif ()
 
 if (BUILD_SIZE_COVERAGE)

include/emio/buffer.hpp

@@ -217,7 +217,7 @@ class span_buffer : public buffer {
   constexpr span_buffer(span_buffer&&) noexcept = delete;
   constexpr span_buffer& operator=(const span_buffer&) = delete;
   constexpr span_buffer& operator=(span_buffer&&) noexcept = delete;
-  constexpr ~span_buffer() override = default;
+  constexpr ~span_buffer() override;
 
   /**
    * Obtains a view over the underlying string object.
@@ -254,6 +254,9 @@ class span_buffer : public buffer {
   std::span<char> span_;
 };
 
+// Out-of-line definition because of a GCC bug (93413). Fixed in GCC 13.
+inline constexpr span_buffer::~span_buffer() = default;
+
 /**
  * This class fulfills the buffer API by providing a fixed-size storage.
  * @tparam StorageSize The size of the storage.

test/compile_test/CMakeLists.txt

@@ -0,0 +1,21 @@
+cmake_minimum_required(VERSION 3.14)
+
+project(emioTests LANGUAGES CXX)
+
+include(${CMAKE_SOURCE_DIR}/cmake/project-is-top-level.cmake)
+include(${CMAKE_SOURCE_DIR}/cmake/folders.cmake)
+
+if (PROJECT_IS_TOP_LEVEL)
+    find_package(emio REQUIRED)
+    enable_testing()
+endif ()
+
+add_executable(emio_compile ../compile_test/compile.cpp)
+
+target_link_libraries(emio_compile
+        emio::emio
+)
+
+target_compile_features(emio_compile PRIVATE cxx_std_20)
+
+add_folders(CompileTest)

test/compile_test/compile.cpp

@@ -0,0 +1,43 @@
+//
+// Created by neubertt on 09.03.2024.
+//
+#include "emio/emio.hpp"
+
+consteval auto created_with_span_buffer() {
+  std::array<char, 5> storage{};
+  emio::span_buffer buf{storage};
+  return storage;
+}
+
+consteval auto created_with_static_buffer() {
+  std::array<char, 5> storage{};
+  emio::static_buffer<5> buf{};
+  std::span<char> area = buf.get_write_area_of(5).value();
+  std::fill(area.begin(), area.end(), 'a');
+  std::copy(buf.view().begin(), buf.view().end(), storage.begin());
+  return storage;
+}
+
+consteval auto created_with_memory_buffer() {
+  std::array<char, 5> storage{};
+  emio::memory_buffer<0> buf{};
+  std::span<char> area = buf.get_write_area_of(5).value();
+  std::fill(area.begin(), area.end(), 'a');
+  std::copy(buf.view().begin(), buf.view().end(), storage.begin());
+  return storage;
+}
+
+consteval auto created_with_iterator_buffer() {
+  std::array<char, 5> storage{};
+  emio::iterator_buffer buf{storage.data()};
+  std::span<char> area = buf.get_write_area_of(5).value();
+  std::fill(area.begin(), area.end(), 'a');
+  return storage;
+}
+
+int main() {
+  created_with_span_buffer();
+  created_with_static_buffer();
+  created_with_memory_buffer();
+  created_with_iterator_buffer();
+}