doc: work around linker warnings about main() being duplicated.

doc/snippets/Magnum-application.cpp

@@ -31,6 +31,10 @@ using namespace Magnum;
 #define DOXYGEN_ELLIPSIS(...) __VA_ARGS__
 #define DOXYGEN_IGNORE(...) __VA_ARGS__
 
+/* Wrapping in a namespace to not conflict with MyApplication defined in
+   Platform.cpp */
+namespace A {
+
 class MyApplication: public Platform::Application {
     public:
         explicit MyApplication(const Arguments& arguments);
@@ -67,6 +71,11 @@ void MyApplication::drawEvent() {
 }
 /* [Timeline-usage] */
 
-int main() {
-    return 0; /* on iOS SDL redefines main to SDL_main and then return is needed */
 }
+
+/* To prevent macOS ranlib from complaining that there are no symbols. OTOH
+   also make sure the name doesn't conflict with any other snippets to avoid
+   linker warnings, AND unlike with `int main()` there now has to be a
+   declaration to avoid -Wmisssing-prototypes */
+void mainMagnum();
+void mainMagnum() {}

doc/snippets/Magnum.cpp

@@ -68,8 +68,11 @@ class MeshResourceLoader: public AbstractResourceLoader<GL::Mesh> {
 }
 #endif
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMagnum();
+void mainMagnum() {
 {
 /* [features-using-namespace] */
 using namespace Corrade;

doc/snippets/MagnumAnimation.cpp

@@ -38,8 +38,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainAnimation();
+void mainAnimation() {
 {
 Float t{};
 {

doc/snippets/MagnumAudio-scenegraph.cpp

@@ -36,8 +36,11 @@
 
 using namespace Magnum;
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainAudioSceneGraph();
+void mainAudioSceneGraph() {
 {
 typedef SceneGraph::Object<SceneGraph::MatrixTransformation3D> Object3D;
 typedef SceneGraph::Scene<SceneGraph::MatrixTransformation3D> Scene3D;

doc/snippets/MagnumAudio.cpp

@@ -55,8 +55,11 @@ CORRADE_PLUGIN_REGISTER(MyAudioImporter, MyNamespace::MyAudioImporter,
     MAGNUM_AUDIO_ABSTRACTIMPORTER_PLUGIN_INTERFACE)
 /* [MAGNUM_AUDIO_ABSTRACTIMPORTER_PLUGIN_INTERFACE] */
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainAudio();
+void mainAudio() {
 {
 /* [Context-isExtensionSupported] */
 if(Audio::Context::current().isExtensionSupported<Audio::Extensions::ALC::SOFTX::HRTF>()) {

doc/snippets/MagnumDebugTools-gl.cpp

@@ -56,7 +56,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainDebugTools();
+void mainDebugTools() {
 {
 SceneGraph::Object<SceneGraph::MatrixTransformation3D>* object{};
 /* [debug-tools-renderers] */

doc/snippets/MagnumDebugTools.cpp

@@ -139,7 +139,11 @@ void MyApp::drawEventAgain() {
 }
 /* [FrameProfiler-usage-console] */
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainDebugTools();
+void mainDebugTools() {
 {
 /* [FrameProfiler-setup-immediate] */
 using std::chrono::high_resolution_clock;

doc/snippets/MagnumGL-application.cpp

@@ -35,6 +35,9 @@ using namespace Magnum;
 
 #define DOXYGEN_ELLIPSIS(...) __VA_ARGS__
 
+/* Namespace used to avoid a conflict with MyApplication defined in
+   MagnumPlatform.cpp where it *has to* be in the root namespace */
+namespace C {
 /* [opengl-wrapping-nocreate] */
 class MyApplication: public Platform::Application {
     DOXYGEN_ELLIPSIS(explicit MyApplication(const Arguments& arguments);)
@@ -57,6 +60,7 @@ MyApplication::MyApplication(const Arguments& arguments):
     _shader = Shaders::PhongGL{};
 }
 /* [opengl-wrapping-nocreate] */
+}
 
 struct A: Platform::Sdl2Application {
 /* [DefaultFramebuffer-usage-viewport] */
@@ -99,8 +103,11 @@ void drawEvent() override {
 /* [Framebuffer-usage-draw] */
 };
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainGLApplication();
+void mainGLApplication() {
 {
 SDL_Window* _window{};
 SDL_GLContext* _otherGLContext{};
@@ -123,6 +130,4 @@ Platform::GLContext::makeCurrent(&other);
 GL::Buffer b; // implicitly tied to `other`
 /* [Context-makeCurrent] */
 }
-
-return 0; /* on iOS SDL redefines main to SDL_main and then return is needed */
 }

doc/snippets/MagnumGL.cpp

@@ -285,8 +285,11 @@ MyShader::MyShader(DOXYGEN_ELLIPSIS(int a)): MyShader{compile(DOXYGEN_ELLIPSIS(a
 }
 #endif
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainGL();
+void mainGL() {
 #ifndef MAGNUM_TARGET_GLES2
 {
 ImageView2D diffuse{PixelFormat::RGBA8Unorm, {}};

doc/snippets/MagnumMaterialTools.cpp

@@ -37,7 +37,11 @@
 
 using namespace Magnum;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMaterialTools();
+void mainMaterialTools() {
 {
 /* -Wnonnull in GCC 11+  "helpfully" says "this is null" if I don't initialize
    the font pointer. I don't care, I just want you to check compilation errors,

doc/snippets/MagnumMath-cpp14.cpp

@@ -28,7 +28,11 @@
 
 using namespace Magnum;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMathCpp14();
+void mainMathCpp14() {
 {
 /* [BitVector-indexing] */
 BitVector4 a{0b0010};

doc/snippets/MagnumMath-stl.cpp

@@ -38,7 +38,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMathStl();
+void mainMathStl() {
 {
 Nanoseconds previousFrameTime;
 /* The (void) is to avoid -Wvexing-parse */

doc/snippets/MagnumMath.cpp

@@ -44,7 +44,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMath();
+void mainMath() {
 {
 /* [matrix-vector-construct] */
 Matrix2x3 a;                            // zero-filled

doc/snippets/MagnumMathAlgorithms.cpp

@@ -35,7 +35,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMathAlgorithms();
+void mainMathAlgorithms() {
 {
 /* [kahanSum] */
 std::vector<Float> data(100000000, 1.0f);

doc/snippets/MagnumMeshTools-gl.cpp

@@ -44,8 +44,11 @@
 
 using namespace Magnum;
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMeshToolsGL();
+void mainMeshToolsGL() {
 {
 Trade::MeshData meshData{MeshPrimitive::Lines, 5};
 /* [compile-external] */

doc/snippets/MagnumMeshTools-stl.cpp

@@ -32,8 +32,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMeshToolsStl();
+void mainMeshToolsStl() {
 {
 /* THe include below is okay as the header guards make it empty */
 /* [generateFlatNormalsInto] */

doc/snippets/MagnumMeshTools.cpp

@@ -47,8 +47,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainMeshTools();
+void mainMeshTools() {
 #ifdef MAGNUM_BUILD_DEPRECATED
 {
 CORRADE_IGNORE_DEPRECATED_PUSH

doc/snippets/MagnumPlatform-custom.cpp

@@ -27,6 +27,8 @@
 
 using namespace Magnum;
 
+/* In this case `int main()` won't conflict with any other snippets as the
+   source is compiled into a standalone static library */
 /* [custom] */
 int main() {
     // Create OpenGL context ...

doc/snippets/MagnumPlatform-portability.cpp

@@ -47,3 +47,5 @@ class MyApplication: public Platform::Application {
 
 MAGNUM_APPLICATION_MAIN(MyApplication)
 /* [application] */
+/* In this case `int main()` won't conflict with any other snippets as the
+   source is compiled into a standalone static library */

doc/snippets/MagnumPlatform-windowless-custom.cpp

@@ -32,6 +32,8 @@ EGLDisplay display{};
 EGLSurface surface{};
 EGLContext anotherContext{};
 
+/* In this case `int main()` won't conflict with any other snippets as the
+   source is compiled into a standalone static library */
 /* [custom] */
 int main(int argc, char** argv) {
     Platform::WindowlessGLContext glContext{{}};

doc/snippets/MagnumPlatform-windowless-thread.cpp

@@ -29,6 +29,8 @@
 
 using namespace Magnum;
 
+/* In this case `int main()` won't conflict with any other snippets as the
+   source is compiled into a standalone static library */
 /* [thread] */
 int main() {
     Platform::WindowlessGLContext glContext{{}};

doc/snippets/MagnumPlatform-windowless.cpp

@@ -51,3 +51,5 @@ int MyApplication::exec() {
 /* main() function implementation */
 MAGNUM_WINDOWLESSAPPLICATION_MAIN(MyApplication)
 /* [windowless] */
+/* In this case `int main()` won't conflict with any other snippets as the
+   source is compiled into a standalone static library */

doc/snippets/MagnumPlatform.cpp

@@ -61,6 +61,8 @@ void MyApplication::drawEvent() {
 /* main() function implementation */
 MAGNUM_APPLICATION_MAIN(MyApplication)
 /* [windowed] */
+/* In this case `int main()` can't be avoided, but other snippets compiled into
+   the same static library all use a different name so it shouldn't conflict */
 
 namespace B {
 

doc/snippets/MagnumPrimitives.cpp

@@ -30,7 +30,11 @@
 
 using namespace Magnum;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainPrimitives();
+void mainPrimitives() {
 {
 Color4 colorLeft, colorRight, colorBottom, colorTop;
 /* [gradient2DHorizontal] */

doc/snippets/MagnumSceneGraph-gl.cpp

@@ -215,7 +215,11 @@ void MyApplication::drawEvent() {
 
 }
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainSceneGraphGL();
+void mainSceneGraphGL() {
 /* [Drawable-usage-instance] */
 Scene3D scene;
 SceneGraph::DrawableGroup3D drawables;
@@ -234,6 +238,4 @@ new RedCubeDrawable{*redCube, &drawables};
     ->translate(Vector3::yAxis(-0.3f))
     .rotateX(30.0_degf);
 /* [Drawable-usage-instance-multiple-inheritance] */
-
-return 0; /* on iOS SDL redefines main to SDL_main and then return is needed */
 }

doc/snippets/MagnumSceneGraph.cpp

@@ -163,7 +163,11 @@ class TransformingFeature: public SceneGraph::AbstractFeature3D {
 
 }
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainSceneGraph();
+void mainSceneGraph() {
 {
 /* [method-chaining] */
 Scene3D scene;

doc/snippets/MagnumSceneTools.cpp

@@ -43,7 +43,11 @@
 
 using namespace Magnum;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainSceneTools();
+void mainSceneTools() {
 {
 /* [filterFieldEntries-shared-mapping] */
 Trade::SceneData scene = DOXYGEN_ELLIPSIS(Trade::SceneData{{}, 0, nullptr, {}});

doc/snippets/MagnumShaderTools.cpp

@@ -62,7 +62,11 @@ CORRADE_PLUGIN_REGISTER(MyShaderConverter, MyNamespace::MyShaderConverter,
     MAGNUM_SHADERTOOLS_ABSTRACTCONVERTER_PLUGIN_INTERFACE)
 /* [MAGNUM_SHADERTOOLS_ABSTRACTCONVERTER_PLUGIN_INTERFACE] */
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainShaderTools();
+void mainShaderTools() {
 {
 /* [AbstractConverter-usage-validation] */
 PluginManager::Manager<ShaderTools::AbstractConverter> manager;

doc/snippets/MagnumShaders-gl.cpp

@@ -82,8 +82,11 @@
 using namespace Magnum;
 using namespace Magnum::Math::Literals;
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainShadersGL();
+void mainShadersGL() {
 /* internal compiler error: in gimplify_init_constructor, at gimplify.c:4271
    on GCC 4.8 in the [60] array */
 #if !defined(CORRADE_TARGET_GCC) || defined(CORRADE_TARGET_CLANG) || __GNUC__ >= 5

doc/snippets/MagnumText-gl.cpp

@@ -45,8 +45,11 @@ namespace {
     Vector2 dpiScaling() { return {}; }
 }
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainTextGL();
+void mainTextGL() {
 {
 /* [AbstractFont-usage] */
 PluginManager::Manager<Text::AbstractFont> manager;

doc/snippets/MagnumText.cpp

@@ -92,8 +92,11 @@ CORRADE_PLUGIN_REGISTER(MyFontConverter, MyNamespace::MyFontConverter,
     MAGNUM_TEXT_ABSTRACTFONTCONVERTER_PLUGIN_INTERFACE)
 /* [MAGNUM_TEXT_ABSTRACTFONTCONVERTER_PLUGIN_INTERFACE] */
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainText();
+void mainText() {
 {
 PluginManager::Manager<Text::AbstractFont> manager;
 Containers::Pointer<Text::AbstractFont> font =

doc/snippets/MagnumTextureTools.cpp

@@ -44,7 +44,11 @@
 
 using namespace Magnum;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainTextureTools();
+void mainTextureTools() {
 {
 /* [AtlasLandfill-usage] */
 Containers::ArrayView<const ImageView2D> images = DOXYGEN_ELLIPSIS({});

doc/snippets/MagnumTrade.cpp

@@ -130,8 +130,11 @@ CORRADE_PLUGIN_REGISTER(MySceneConverter, MyNamespace::MySceneConverter,
     MAGNUM_TRADE_ABSTRACTSCENECONVERTER_PLUGIN_INTERFACE)
 /* [MAGNUM_TRADE_ABSTRACTSCENECONVERTER_PLUGIN_INTERFACE] */
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainTrade();
+void mainTrade() {
 {
 Vector2i size;
 /* [AbstractImageConverter-usage-file] */

doc/snippets/MagnumVk.cpp

@@ -124,8 +124,11 @@ MyApplication::MyApplication(DOXYGEN_ELLIPSIS(Vk::Instance& instance)) {
 
 }
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainVk();
+void mainVk() {
 {
 /* [wrapping-extending-create-info] */
 Vk::InstanceCreateInfo info{DOXYGEN_ELLIPSIS()};

doc/snippets/platforms-html5.cpp

@@ -28,7 +28,11 @@
 
 using namespace Corrade;
 
-int main() {
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainPlatformsHtml5();
+void mainPlatformsHtml5() {
 {
 /* [emasm-dollar] */
 #pragma GCC diagnostic push

doc/snippets/plugins.cpp

@@ -45,8 +45,11 @@
 
 using namespace Magnum;
 
-int main() {
-
+/* Make sure the name doesn't conflict with any other snippets to avoid linker
+   warnings, unlike with `int main()` there now has to be a declaration to
+   avoid -Wmisssing-prototypes */
+void mainPlugins();
+void mainPlugins() {
 /* [loading] */
 {
     PluginManager::Manager<Trade::AbstractImporter> manager;