From b3e9448ff4efcc9c6773889cf422f295044bcde0 Mon Sep 17 00:00:00 2001
From: Thomas Harte <thomas.harte@gmail.com>
Date: Tue, 3 Feb 2026 13:07:40 -0500
Subject: [PATCH] Go further in avoiding std::function.

---
 Analyser/Static/Atari2600/StaticAnalyser.cpp           | 2 +-
 Components/1770/1770.cpp                               | 4 +++-
 Components/1770/1770.hpp                               | 7 ++++++-
 Machines/Commodore/Vic-20/Vic20.cpp                    | 5 ++++-
 OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm | 5 ++++-
 5 files changed, 18 insertions(+), 5 deletions(-)

diff --git a/Analyser/Static/Atari2600/StaticAnalyser.cpp b/Analyser/Static/Atari2600/StaticAnalyser.cpp
index 9a1c29632..714310dd9 100644
--- a/Analyser/Static/Atari2600/StaticAnalyser.cpp
+++ b/Analyser/Static/Atari2600/StaticAnalyser.cpp
@@ -23,7 +23,7 @@ static void DeterminePagingFor2kCartridge(Target &target, const Storage::Cartrid
 	// A CommaVid start address needs to be outside of its RAM.
 	if(entry_address < 0x1800 || break_address < 0x1800) return;
 
-	std::function<std::size_t(uint16_t address)> high_location_mapper = [](uint16_t address) {
+	auto high_location_mapper = [](uint16_t address) {
 		address &= 0x1fff;
 		return size_t(address - 0x1800);
 	};
diff --git a/Components/1770/1770.cpp b/Components/1770/1770.cpp
index 6928aa279..7b875552d 100644
--- a/Components/1770/1770.cpp
+++ b/Components/1770/1770.cpp
@@ -829,7 +829,9 @@ void WD1770::posit_event(const int new_event_type) {
 	END_SECTION()
 }
 
-void WD1770::update_status(const std::function<void(Status &)> updater) {
+template <typename FuncT>
+requires std::invocable<FuncT, WD1770::Status &>
+void WD1770::update_status(FuncT &&updater) {
 	const Status old_status = status_;
 
 	if(delegate_) {
diff --git a/Components/1770/1770.hpp b/Components/1770/1770.hpp
index a32888c6b..caad49d6c 100644
--- a/Components/1770/1770.hpp
+++ b/Components/1770/1770.hpp
@@ -10,6 +10,8 @@
 
 #include "Storage/Disk/Controller/MFMDiskController.hpp"
 
+#include <concepts>
+
 namespace WD {
 
 /*!
@@ -112,7 +114,10 @@ private:
 	int distance_into_section_;
 
 	int step_direction_;
-	void update_status(std::function<void(Status &)> updater);
+
+	template <typename FuncT>
+	requires std::invocable<FuncT, Status &>
+	void update_status(FuncT &&);
 
 	// Events
 	enum Event1770: int {
diff --git a/Machines/Commodore/Vic-20/Vic20.cpp b/Machines/Commodore/Vic-20/Vic20.cpp
index 6620c6e5b..4dfeb9b27 100644
--- a/Machines/Commodore/Vic-20/Vic20.cpp
+++ b/Machines/Commodore/Vic-20/Vic20.cpp
@@ -35,6 +35,7 @@
 
 #include <algorithm>
 #include <array>
+#include <concepts>
 #include <cstdint>
 #include <optional>
 
@@ -740,7 +741,9 @@ private:
 	const uint8_t *processor_read_memory_map_[64]{};
 	uint8_t *processor_write_memory_map_[64]{};
 
-	void write_to_map(const std::function<void(uint16_t, size_t)> &store, uint16_t address, size_t length) {
+	template <typename FuncT>
+	requires std::invocable<FuncT, uint16_t, size_t>
+	void write_to_map(FuncT &&store, uint16_t address, size_t length) {
 		address >>= 10;
 		length >>= 10;
 		size_t offset = 0;
diff --git a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm
index 0f92972a6..c60bbdf16 100644
--- a/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
+++ b/OSBindings/Mac/Clock Signal/ScanTarget/CSScanTarget.mm	
@@ -13,6 +13,7 @@
 #include <algorithm>
 #include <atomic>
 #include <cmath>
+#include <concepts>
 #include <optional>
 
 #include "BufferingScanTarget.hpp"
@@ -142,11 +143,13 @@ constexpr MTLResourceOptions SharedResourceOptionsStandard =
 constexpr MTLResourceOptions SharedResourceOptionsTexture =
 	MTLResourceCPUCacheModeWriteCombined | MTLResourceStorageModeManaged;
 
+template <typename FuncT>
+requires std::invocable<FuncT, size_t, size_t>
 void range_perform(
 	const size_t start,
 	const size_t end,
 	const size_t size,
-	const std::function<void(size_t start, size_t length)> &func
+	const FuncT &&func
 ) {
 	if(start == end) return;
 	if(start < end) {