Apply std::invocable.

Outputs/OpenGL/OpenGL.hpp

@@ -51,14 +51,16 @@ inline void test_gl_error() {}
 #endif
 
 #ifndef NDEBUG
-template <typename Func>
-inline void test_gl(const Func &&perform) {
+template <typename FuncT>
+requires std::invocable<FuncT>
+inline void test_gl(const FuncT &&perform) {
 	perform();
 	test_gl_error();
 }
 #else
-template <typename Func>
-inline void test_gl(const Func &&perform) {
+template <typename FuncT>
+requires std::invocable<FuncT>
+inline void test_gl(const FuncT &&perform) {
 	perform();
 }
 #endif

Outputs/OpenGL/Primitives/Shader.cpp

@@ -9,6 +9,7 @@
 #include "Shader.hpp"
 
 #include "Outputs/Log.hpp"
+
 #include <vector>
 
 using namespace Outputs::Display::OpenGL;
@@ -221,6 +222,7 @@ void Shader::enable_vertex_attribute_with_pointer(
 }
 
 template <typename FuncT>
+requires std::invocable<FuncT, GLint>
 void Shader::with_location(const std::string &name, FuncT &&function) {
 	const GLint location = glGetUniformLocation(shader_program_, name.c_str());
 	if(location == -1) {

Outputs/OpenGL/Primitives/Shader.hpp

@@ -11,6 +11,7 @@
 #include "Outputs/OpenGL/API.hpp"
 #include "Outputs/OpenGL/OpenGL.hpp"
 
+#include <concepts>
 #include <functional>
 #include <mutex>
 #include <string>
@@ -158,6 +159,7 @@ private:
 	);
 
 	template <typename FuncT>
+	requires std::invocable<FuncT, GLint>
 	void with_location(const std::string &, FuncT &&);
 
 	GLuint compile_shader(const std::string &source, GLenum type);

SignalProcessing/FIRFilter.hpp

@@ -19,6 +19,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cmath>
+#include <concepts>
 #include <functional>
 #include <iterator>
 #include <numeric>
@@ -144,11 +145,12 @@ public:
 		return coefficients_.end();
 	}
 
-	template <typename IteratorT>
+	template <typename IteratorT, typename FuncT>
+	requires std::invocable<FuncT, IteratorT, CoefficientType>
 	void copy_to(
 		IteratorT begin,
 		IteratorT end,
-		const std::function<void(IteratorT, CoefficientType)> &applier
+		FuncT &&applier
 	) const {
 		auto dest = begin;
 		auto src = coefficients_.begin();

Storage/Disk/Controller/DiskController.hpp

@@ -15,6 +15,8 @@
 #include "ClockReceiver/ClockReceiver.hpp"
 #include "ClockReceiver/ClockingHintSource.hpp"
 
+#include <concepts>
+
 namespace Storage::Disk {
 
 /*!
@@ -133,7 +135,9 @@ protected:
 		return *drives_[index];
 	}
 
-	void for_all_drives(const std::function<void(Drive &, size_t)> &func) {
+	template <typename FuncT>
+	requires std::invocable<FuncT, Drive &, size_t>
+	void for_all_drives(FuncT &&func) {
 		size_t index = 0;
 		for(auto &drive: drives_) {
 			func(*drive, index);