merge ES.74 into ES.6, leaving a redirect behind

closes #1858

CppCoreGuidelines.md

@@ -10212,7 +10212,10 @@ In this case, it might be a good idea to factor out the read:
 
 ##### Reason
 
-Readability. Minimize resource retention.
+Readability.
+Limit the loop variable visibility to the scope of the loop.
+Avoid using the loop variable for other purposes after the loop.
+Minimize resource retention.
 
 ##### Example
 
@@ -10233,11 +10236,24 @@ Readability. Minimize resource retention.
         }
     }
 
+##### Example, don't
+
+    int j;                            // BAD: j is visible outside the loop
+    for (j = 0; j < 100; ++j) {
+        // ...
+    }
+    // j is still visible here and isn't needed
+
+**See also**: [Don't use a variable for two unrelated purposes](#Res-recycle)
+
 ##### Enforcement
 
-* Flag loop variables declared before the loop and not used after the loop
+* Warn when a variable modified inside the `for`-statement is declared outside the loop and not being used outside the loop.
 * (hard) Flag loop variables declared before the loop and used after the loop for an unrelated purpose.
 
+**Discussion**: Scoping the loop variable to the loop body also helps code optimizers greatly. Recognizing that the induction variable
+is only accessible in the loop body unblocks optimizations such as hoisting, strength reduction, loop-invariant code motion, etc.
+
 ##### C++17 and C++20 example
 
 Note: C++17 and C++20 also add `if`, `switch`, and range-`for` initializer statements. These require C++17 and C++20 support.
@@ -10255,8 +10271,6 @@ Note: C++17 and C++20 also add `if`, `switch`, and range-`for` initializer state
 * Flag selection/loop variables declared before the body and not used after the body
 * (hard) Flag selection/loop variables declared before the body and used after the body for an unrelated purpose.
 
-
-
 ### <a name="Res-name-length"></a>ES.7: Keep common and local names short, and keep uncommon and non-local names longer
 
 ##### Reason
@@ -12718,39 +12732,7 @@ Flag actions in `for`-initializers and `for`-increments that do not relate to th
 
 ### <a name="Res-for-init"></a>ES.74: Prefer to declare a loop variable in the initializer part of a `for`-statement
 
-##### Reason
+See [ES.6](#Res-cond)
-
-Limit the loop variable visibility to the scope of the loop.
-Avoid using the loop variable for other purposes after the loop.
-
-##### Example
-
-    for (int i = 0; i < 100; ++i) {   // GOOD: i var is visible only inside the loop
-        // ...
-    }
-
-##### Example, don't
-
-    int j;                            // BAD: j is visible outside the loop
-    for (j = 0; j < 100; ++j) {
-        // ...
-    }
-    // j is still visible here and isn't needed
-
-**See also**: [Don't use a variable for two unrelated purposes](#Res-recycle)
-
-##### Example
-
-    for (string s; cin >> s; ) {
-        cout << s << '\n';
-    }
-
-##### Enforcement
-
-Warn when a variable modified inside the `for`-statement is declared outside the loop and not being used outside the loop.
-
-**Discussion**: Scoping the loop variable to the loop body also helps code optimizers greatly. Recognizing that the induction variable
-is only accessible in the loop body unblocks optimizations such as hoisting, strength reduction, loop-invariant code motion, etc.
 
 ### <a name="Res-do"></a>ES.75: Avoid `do`-statements