[llvm-commits] [llvm] r135389 - /llvm/trunk/include/llvm/ADT/ArrayRef.h

[Frits van Bommel]

Author: fvbommel
Date: Mon Jul 18 06:58:53 2011
New Revision: 135389

URL: http://llvm.org/viewvc/llvm-project?rev=135389&view=rev
Log:
Introduce the 'makeArrayRef(...)' family of functions, which fills a similar role for ArrayRef<> as std::make_pair() fills for std::pair<>: they return the right instantiation of ArrayRef<T> based on the types of the parameters.

They mostly mirror the ArrayRef constructors, with two exceptions:
 * There's no function mirroring the default constructor because it wouldn't have any parameters to deduce the right ArrayRef<T> from.
 * There's an explicit SmallVector<T> overload in addition to the SmallVectorImpl<T> overload. Without it, the single-element overload would try to create an ArrayRef<Smallvector<T> > because it's a better match according to the overloading rules. (And both overloads are used in the current tree, so neither is redundant)

Modified:
    llvm/trunk/include/llvm/ADT/ArrayRef.h

Modified: llvm/trunk/include/llvm/ADT/ArrayRef.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/ADT/ArrayRef.h?rev=135389&r1=135388&r2=135389&view=diff
==============================================================================
--- llvm/trunk/include/llvm/ADT/ArrayRef.h (original)
+++ llvm/trunk/include/llvm/ADT/ArrayRef.h Mon Jul 18 06:58:53 2011
@@ -147,7 +147,53 @@
     
     /// @}
   };
-  
+
+  /// @name ArrayRef Convenience constructors
+  /// @{
+
+  /// Construct an ArrayRef from a single element.
+  template<typename T>
+  ArrayRef<T> makeArrayRef(const T &OneElt) {
+    return OneElt;
+  }
+
+  /// Construct an ArrayRef from a pointer and length.
+  template<typename T>
+  ArrayRef<T> makeArrayRef(const T *data, size_t length) {
+    return ArrayRef<T>(data, length);
+  }
+
+  /// Construct an ArrayRef from a range.
+  template<typename T>
+  ArrayRef<T> makeArrayRef(const T *begin, const T *end) {
+    return ArrayRef<T>(begin, end);
+  }
+
+  /// Construct an ArrayRef from a SmallVector.
+  template <typename T>
+  ArrayRef<T> makeArrayRef(const SmallVectorImpl<T> &Vec) {
+    return Vec;
+  }
+
+  /// Construct an ArrayRef from a SmallVector.
+  template <typename T, unsigned N>
+  ArrayRef<T> makeArrayRef(const SmallVector<T, N> &Vec) {
+    return Vec;
+  }
+
+  /// Construct an ArrayRef from a std::vector.
+  template<typename T>
+  ArrayRef<T> makeArrayRef(const std::vector<T> &Vec) {
+    return Vec;
+  }
+
+  /// Construct an ArrayRef from a C array.
+  template<typename T, size_t N>
+  ArrayRef<T> makeArrayRef(const T (&Arr)[N]) {
+    return Arr;
+  }
+
+  /// @}
   /// @name ArrayRef Comparison Operators
   /// @{