Re-landing "Refactoring cl::list_storage from "is a" to "has a" std::vector."

[oota-llvm.git] / include / llvm / Support / SMLoc.h

diff --git a/include/llvm/Support/SMLoc.h b/include/llvm/Support/SMLoc.h
index 7e0811a1afc7e43904375b26c61898c61300fc35..d5b4c57a8fd6e8d547a3ab536d28dba6b82fc5f1 100644 (file)
--- a/include/llvm/Support/SMLoc.h
+++ b/include/llvm/Support/SMLoc.h
@@ -12,21 +12,20 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef SUPPORT_SMLOC_H
-#define SUPPORT_SMLOC_H
+#ifndef LLVM_SUPPORT_SMLOC_H
+#define LLVM_SUPPORT_SMLOC_H
 
 #include <cassert>
 
 namespace llvm {
 
-/// SMLoc - Represents a location in source code.
+/// Represents a location in source code.
 class SMLoc {
   const char *Ptr;
 public:
-  SMLoc() : Ptr(0) {}
-  SMLoc(const SMLoc &RHS) : Ptr(RHS.Ptr) {}
+  SMLoc() : Ptr(nullptr) {}
 
-  bool isValid() const { return Ptr != 0; }
+  bool isValid() const { return Ptr != nullptr; }
 
   bool operator==(const SMLoc &RHS) const { return RHS.Ptr == Ptr; }
   bool operator!=(const SMLoc &RHS) const { return RHS.Ptr != Ptr; }
@@ -40,9 +39,11 @@ public:
   }
 };
 
-/// SMRange - Represents a range in source code.  Note that unlike standard STL
-/// ranges, the locations specified are considered to be *inclusive*.  For
-/// example, [X,X] *does* include X, it isn't an empty range.
+/// Represents a range in source code.
+///
+/// SMRange is implemented using a half-open range, as is the convention in C++.
+/// In the string "abc", the range (1,3] represents the substring "bc", and the
+/// range (2,2] represents an empty range between the characters "b" and "c".
 class SMRange {
 public:
   SMLoc Start, End;