diff --git a/Numeric/BitSpread.hpp b/Numeric/BitSpread.hpp
index 56553aff1..220ebacab 100644
--- a/Numeric/BitSpread.hpp
+++ b/Numeric/BitSpread.hpp
@@ -16,7 +16,7 @@ namespace Numeric {
 /// keeping the least-significant bit in its original position.
 ///
 /// i.e. if @c input is abcdefgh then the result is 0a0b0c0d0e0f0g0h
-constexpr uint16_t spread_bits(uint8_t input) {
+constexpr uint16_t spread_bits(const uint8_t input) {
 	uint16_t result = uint16_t(input);				// 0000 0000 abcd efgh
 	result = (result | (result << 4)) & 0x0f0f;		// 0000 abcd 0000 efgh
 	result = (result | (result << 2)) & 0x3333;		// 00ab 00cd 00ef 00gh
@@ -26,11 +26,12 @@ constexpr uint16_t spread_bits(uint8_t input) {
 /// Performs the opposite action to @c spread_bits; given the 16-bit input
 /// @c abcd @c efgh @c ijkl @c mnop, returns the byte value @c bdfhjlnp
 /// i.e. every other bit is retained, keeping the least-significant bit in place.
-constexpr uint8_t unspread_bits(uint16_t input) {
-	input &= 0x5555;								// 0a0b 0c0d 0e0f 0g0h
-	input = (input | (input >> 1)) & 0x3333;		// 00ab 00cd 00ef 00gh
-	input = (input | (input >> 2)) & 0x0f0f;		// 0000 abcd 0000 efgh
-	return uint8_t(input | (input >> 4));			// 0000 0000 abcd efgh
+constexpr uint8_t unspread_bits(const uint16_t input) {
+	uint16_t result = input;
+	result &= 0x5555;								// 0a0b 0c0d 0e0f 0g0h
+	result = (result | (result >> 1)) & 0x3333;		// 00ab 00cd 00ef 00gh
+	result = (result | (result >> 2)) & 0x0f0f;		// 0000 abcd 0000 efgh
+	return uint8_t(result | (result >> 4));			// 0000 0000 abcd efgh
 }
 
 }
diff --git a/Numeric/LFSR.hpp b/Numeric/LFSR.hpp
index f2cf4f7d8..58f0959f6 100644
--- a/Numeric/LFSR.hpp
+++ b/Numeric/LFSR.hpp
@@ -61,7 +61,7 @@ public:
 
 		An initial value of 0 is invalid.
 	*/
-	LFSR(IntType initial_value) : value_(initial_value) {}
+	LFSR(const IntType initial_value) : value_(initial_value) {}
 
 	/*!
 		Advances the LSFR, returning either an @c IntType of value @c 1 or @c 0,
diff --git a/Numeric/NumericCoder.hpp b/Numeric/NumericCoder.hpp
index 6644a5ead..10252b6db 100644
--- a/Numeric/NumericCoder.hpp
+++ b/Numeric/NumericCoder.hpp
@@ -30,13 +30,13 @@ namespace Numeric {
 template <int... Sizes> class NumericCoder {
 public:
 	/// Modifies @c target to hold @c value at @c index.
-	template <int index> static void encode(int &target, int value) {
+	template <int index> static void encode(int &target, const int value) {
 		static_assert(index < sizeof...(Sizes), "Index must be within range");
 		NumericEncoder<Sizes...>::template encode<index>(target, value);
 	}
 
 	/// @returns The value from @c source at @c index.
-	template <int index> static int decode(int source) {
+	template <int index> static int decode(const int source) {
 		static_assert(index < sizeof...(Sizes), "Index must be within range");
 		return NumericDecoder<Sizes...>::template decode<index>(source);
 	}
@@ -45,7 +45,7 @@ private:
 
 	template <int size, int... Tail>
 	struct NumericEncoder {
-		template <int index, int i = 0, int divider = 1> static void encode(int &target, int value) {
+		template <int index, int i = 0, int divider = 1> static void encode(int &target, const int value) {
 			if constexpr (i == index) {
 				const int suffix = target % divider;
 				target /= divider;
@@ -61,7 +61,7 @@ private:
 
 	template <int size, int... Tail>
 	struct NumericDecoder {
-		template <int index, int i = 0, int divider = 1> static int decode(int source) {
+		template <int index, int i = 0, int divider = 1> static int decode(const int source) {
 			if constexpr (i == index) {
 				return (source / divider) % size;
 			} else {