saturate extract

Author: pwojcikdev

nano/core_test/numbers.cpp

@@ -1,5 +1,6 @@
 #include <nano/lib/balance_formatting.hpp>
 #include <nano/lib/numbers.hpp>
+#include <nano/lib/saturate.hpp>
 #include <nano/lib/numbers_templ.hpp>
 #include <nano/lib/ratios.hpp>
 #include <nano/secure/common.hpp>

nano/lib/numbers.hpp

@@ -489,33 +489,6 @@ namespace difficulty
 	uint64_t from_multiplier (double const, uint64_t const);
 	double to_multiplier (uint64_t const, uint64_t const);
 }
-
-/**
- * Add to or substract from a value without overflow
- * TODO: C++26 replace with std::add_sat and std::sub_sat
- */
-template <typename T>
-T add_sat (T const & value, T const & diff) noexcept
-{
-	static_assert (std::numeric_limits<T>::is_specialized, "std::numeric_limits<T> must be specialized");
-	return (value > std::numeric_limits<T>::max () - diff) ? std::numeric_limits<T>::max () : value + diff;
-}
-template <typename T>
-T sub_sat (T const & value, T const & diff) noexcept
-{
-	static_assert (std::numeric_limits<T>::is_specialized, "std::numeric_limits<T> must be specialized");
-	return (value < std::numeric_limits<T>::min () + diff) ? std::numeric_limits<T>::min () : value - diff;
-}
-template <typename T>
-T inc_sat (T const & value) noexcept
-{
-	return add_sat (value, static_cast<T> (1));
-}
-template <typename T>
-T dec_sat (T const & value) noexcept
-{
-	return sub_sat (value, static_cast<T> (1));
-}
 }
 
 /*

nano/lib/saturate.hpp

@@ -0,0 +1,30 @@
+#pragma once
+
+#include <limits>
+
+namespace nano
+{
+// Saturating arithmetic — clamps at numeric limits instead of overflowing
+template <typename T>
+T add_sat (T const & value, T const & diff) noexcept
+{
+	static_assert (std::numeric_limits<T>::is_specialized, "std::numeric_limits<T> must be specialized");
+	return (value > std::numeric_limits<T>::max () - diff) ? std::numeric_limits<T>::max () : value + diff;
+}
+template <typename T>
+T sub_sat (T const & value, T const & diff) noexcept
+{
+	static_assert (std::numeric_limits<T>::is_specialized, "std::numeric_limits<T> must be specialized");
+	return (value < std::numeric_limits<T>::min () + diff) ? std::numeric_limits<T>::min () : value - diff;
+}
+template <typename T>
+T inc_sat (T const & value) noexcept
+{
+	return add_sat (value, static_cast<T> (1));
+}
+template <typename T>
+T dec_sat (T const & value) noexcept
+{
+	return sub_sat (value, static_cast<T> (1));
+}
+}

nano/node/backlog_scan.cpp

@@ -1,3 +1,4 @@
+#include <nano/lib/saturate.hpp>
 #include <nano/lib/stats.hpp>
 #include <nano/lib/thread_roles.hpp>
 #include <nano/lib/threading.hpp>

nano/node/json_handler.cpp

@@ -1,4 +1,5 @@
 #include <nano/lib/block_type.hpp>
+#include <nano/lib/saturate.hpp>
 #include <nano/lib/blockbuilders.hpp>
 #include <nano/lib/blocks.hpp>
 #include <nano/lib/config.hpp>

nano/node/pruning.cpp

@@ -1,4 +1,5 @@
 #include <nano/lib/logging.hpp>
+#include <nano/lib/saturate.hpp>
 #include <nano/lib/stats.hpp>
 #include <nano/lib/thread_roles.hpp>
 #include <nano/lib/threading.hpp>

nano/node/vote_rebroadcaster.cpp

@@ -1,4 +1,5 @@
 #include <nano/lib/assert.hpp>
+#include <nano/lib/saturate.hpp>
 #include <nano/lib/interval.hpp>
 #include <nano/lib/logging.hpp>
 #include <nano/lib/numbers_templ.hpp>

nano/store/crawler.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <nano/lib/numbers.hpp>
+#include <nano/lib/saturate.hpp>
 #include <nano/lib/utility.hpp>
 #include <nano/store/transaction.hpp>