Merge #15139: util: Remove [U](BEGIN|END) macros

332b3dd7c1 util: Make ToLower and ToUpper take a char (Wladimir J. van der Laan)
edb5bb3500 util: remove unused [U](BEGIN|END) macros (Wladimir J. van der Laan)
7fa238c701 Replace use of BEGIN and END macros on uint256 (Wladimir J. van der Laan)

Pull request description:

  Two cleanups in `util/strencodings.h`:

  - Remove `[U](BEGIN|END)` macros — The only use of these was in the Merkle tree code with `uint256` which has its own `begin` and `end` methods which are better.
  - Make ToLower and ToUpper take a char — Unfortunately, `std::string` elements are (bare) chars. As these are the most likely type to be passed to these functions, make them use char instead of unsigned char. This avoids some casts.

Tree-SHA512: 96c8292e1b588d3d7fde95c2e98ad4e7eb75e7baab40a8e8e8209d4e8e7a1bd3b6846601d20976be34a9daabefc50cbc23f3b04200af17d0dfc857c4ec42aca7

src/merkleblock.cpp

@@ -83,7 +83,7 @@ uint256 CPartialMerkleTree::CalcHash(int height, unsigned int pos, const std::ve
         else
             right = left;
         // combine subhashes
-        return Hash(BEGIN(left), END(left), BEGIN(right), END(right));
+        return Hash(left.begin(), left.end(), right.begin(), right.end());
     }
 }
 
@@ -139,7 +139,7 @@ uint256 CPartialMerkleTree::TraverseAndExtract(int height, unsigned int pos, uns
             right = left;
         }
         // and combine them before returning
-        return Hash(BEGIN(left), END(left), BEGIN(right), END(right));
+        return Hash(left.begin(), left.end(), right.begin(), right.end());
     }
 }
 

src/test/merkle_tests.cpp

@@ -13,9 +13,9 @@ static uint256 ComputeMerkleRootFromBranch(const uint256& leaf, const std::vecto
     uint256 hash = leaf;
     for (std::vector<uint256>::const_iterator it = vMerkleBranch.begin(); it != vMerkleBranch.end(); ++it) {
         if (nIndex & 1) {
-            hash = Hash(BEGIN(*it), END(*it), BEGIN(hash), END(hash));
+            hash = Hash(it->begin(), it->end(), hash.begin(), hash.end());
         } else {
-            hash = Hash(BEGIN(hash), END(hash), BEGIN(*it), END(*it));
+            hash = Hash(hash.begin(), hash.end(), it->begin(), it->end());
         }
         nIndex >>= 1;
     }

src/test/util_tests.cpp

@@ -1297,7 +1297,7 @@ BOOST_AUTO_TEST_CASE(test_ToLower)
     BOOST_CHECK_EQUAL(ToLower('Z'), 'z');
     BOOST_CHECK_EQUAL(ToLower('['), '[');
     BOOST_CHECK_EQUAL(ToLower(0), 0);
-    BOOST_CHECK_EQUAL(ToLower(255), 255);
+    BOOST_CHECK_EQUAL(ToLower('\xff'), '\xff');
 
     std::string testVector;
     Downcase(testVector);
@@ -1319,7 +1319,7 @@ BOOST_AUTO_TEST_CASE(test_ToUpper)
     BOOST_CHECK_EQUAL(ToUpper('z'), 'Z');
     BOOST_CHECK_EQUAL(ToUpper('{'), '{');
     BOOST_CHECK_EQUAL(ToUpper(0), 0);
-    BOOST_CHECK_EQUAL(ToUpper(255), 255);
+    BOOST_CHECK_EQUAL(ToUpper('\xff'), '\xff');
 }
 
 BOOST_AUTO_TEST_CASE(test_Capitalize)

src/util/strencodings.cpp

@@ -620,7 +620,7 @@ std::string HexStr(const Span<const uint8_t> s)
 
 void Downcase(std::string& str)
 {
-    std::transform(str.begin(), str.end(), str.begin(), [](unsigned char c){return ToLower(c);});
+    std::transform(str.begin(), str.end(), str.begin(), [](char c){return ToLower(c);});
 }
 
 std::string Capitalize(std::string str)

src/util/strencodings.h

@@ -16,10 +16,6 @@
 #include <string>
 #include <vector>
 
-#define BEGIN(a)            ((char*)&(a))
-#define END(a)              ((char*)&((&(a))[1]))
-#define UBEGIN(a)           ((unsigned char*)&(a))
-#define UEND(a)             ((unsigned char*)&((&(a))[1]))
 #define ARRAYLEN(array)     (sizeof(array)/sizeof((array)[0]))
 
 /** Used by SanitizeString() */
@@ -196,7 +192,7 @@ bool ConvertBits(const O& outfn, I it, I end) {
  * @return          the lowercase equivalent of c; or the argument
  *                  if no conversion is possible.
  */
-constexpr unsigned char ToLower(unsigned char c)
+constexpr char ToLower(char c)
 {
     return (c >= 'A' && c <= 'Z' ? (c - 'A') + 'a' : c);
 }
@@ -217,7 +213,7 @@ void Downcase(std::string& str);
  * @return          the uppercase equivalent of c; or the argument
  *                  if no conversion is possible.
  */
-constexpr unsigned char ToUpper(unsigned char c)
+constexpr char ToUpper(char c)
 {
     return (c >= 'a' && c <= 'z' ? (c - 'a') + 'A' : c);
 }