Fixed template bug in serialization

bit_hacks.h

@@ -1,75 +0,0 @@
-#pragma once
-
-//	We should template this to use __popcnt64 if available
-//	but that is premature optimization
-inline uint64_t bitcount(uint64_t c) {
-	c = c - ((c >> 1) & 0x5555555555555555);
-	c = ((c >> 2) & 0x3333333333333333) +
-		(c & 0x3333333333333333);
-	c = ((c >> 4) + c) & 0x0F0F0F0F0F0F0F0F;
-	c = ((c >> 8) + c) & 0x00FF00FF00FF00FF;
-	c = ((c >> 16) + c) & 0x0000FFFF0000FFFF;
-	c = ((c >> 32) + c) & 0x00000000FFFFFFFF;
-	return c;
-}
-
-// http://graphics.stanford.edu/~seander/bithacks.html#IntegerLog  "Bit Hacks"
-//	Find ⌊log2⌋
-//	We should template this to use lzcnt64, __builtin_clz or _BitScanReverse if available,
-//	but that is premature optimization.
-inline auto rounded_log2(uint32_t v) {
-	// This algorithm extends to 64 bits, by adding a step, shrinks to sixteen bits by removing a step.
-	decltype(v) r{ 0 }, s;
-	//	This redundant initialization and redundant |= of r can be eliminated,
-	//	but eliminating it obfuscates the simplicity of the algorithm.
-	s = (v > 0xFFFF) << 4; v >>= s; r |= s;
-	s = (v > 0x00FF) << 3; v >>= s; r |= s;
-	s = (v > 0x000F) << 2; v >>= s; r |= s;
-	s = (v > 0x0003) << 1; v >>= s; r |= s;
-	r |= (v >> 1);
-	// result of ⌊log2(v)⌋ is in r
-	return r;
-}
-
-//	For trailing bits, consider int __builtin_ctz (unsigned int x)
-//	http://graphics.stanford.edu/~seander/bithacks.html#ZerosOnRightLinear
-
-//	Count the consecutive trailing zero bits
-inline auto trailing_zero_bits(uint64_t v) {
-	unsigned int c;
-	if (v & 0x3F) {
-		v = (v ^ (v - 1)) >> 1;  // Set v's trailing 0s to 1s and zero rest
-		for (c = 0; v; c++) {
-			v >>= 1;
-		}
-	}
-	else {
-		c = 1;
-		if ((v & 0xffffffff) == 0) {
-			v >>= 32;
-			c += 32;
-		}
-		if ((v & 0xffff) == 0) {
-			v >>= 16;
-			c += 16;
-		}
-		if ((v & 0xff) == 0){
-			v >>= 8;
-			c += 8;
-		}
-		if ((v & 0xf) == 0){
-			v >>= 4;
-			c += 4;
-		}
-		if ((v & 0x3) == 0) {
-			v >>= 2;
-			c += 2;
-		}
-		if ((v & 0x1) == 0) {
-			v >>= 1;
-			c += 1;
-		}
-		c -= v & 0x01;
-	}
-	return c;
-}

introspection_of_standard_C_types.h

@@ -14,11 +14,11 @@ namespace ro {
 
 	template <class T>
 	constexpr bool is_standard_unsigned_integer =
-		_Is_any_of_v<std::remove_cv_t<T>, unsigned char, unsigned short, unsigned int, unsigned long, unsigned long long>;
+		_Is_any_of_v<std::remove_cvref<T>::type, unsigned char, unsigned short, unsigned int, unsigned long, unsigned long long>;
 
 	template <class T>
 	constexpr bool is_standard_signed_integer =
-		_Is_any_of_v<std::remove_cv_t<T>, signed char, signed short, signed int, signed long, signed long long>;
+		_Is_any_of_v<std::remove_cvref<T>::type, signed char, signed short, signed int, signed long, signed long long>;
 
 	//  A compile time test to see if desired casts work, and make sure that
 	//	undesired casts do not work

ristretto255.h

@@ -105,11 +105,11 @@ namespace ro {
 		}
 	};
 
-	//	This template generates a span over const unsigned bytes for
-	//	any range over bytes, such as a C array or an std::array
+	//	This template generates a span over an indexable byte type,
+	//	such as a C array or an std::array, but not pointers
 	template < typename T>
 	std::enable_if_t<
-		sizeof(std::size(std::declval<T>())) >= sizeof(int) &&
+		!std::is_pointer<T>::value   &&
 		sizeof(std::declval<T>()[0]) == 1,
 		std::span<const byte>
 	> serialize(const T& a) {
@@ -453,7 +453,7 @@ namespace ristretto255 {
 		}
 
 		template < typename T>
-		decltype(ro::serialize(std::declval<T>()), hsh<hashsize>())&
+		decltype(ro::serialize(std::declval<std::remove_cvref<T>::type >()), hsh<hashsize>())&
 			operator <<(const T & j) {
 			return *this << ro::serialize(j);
 		}
@@ -468,7 +468,7 @@ namespace ristretto255 {
 			}
 		}
 
-		hsh<hashsize>& operator <<(const std::span<const byte>& j) {
+		hsh<hashsize>& operator <<(const std::span<const byte> j) {
 			int i = crypto_generichash_blake2b_update(
 				&st,
 				&j[0],