diff --git a/include/llvm/ADT/ArrayRef.h b/include/llvm/ADT/ArrayRef.h index a801e985d15..014db620715 100644 --- a/include/llvm/ADT/ArrayRef.h +++ b/include/llvm/ADT/ArrayRef.h @@ -173,7 +173,13 @@ namespace llvm { return ArrayRef(data()+N, M); } - // \brief Drop the last \p N elements of the array. + /// \brief Drop the first \p N elements of the array. + ArrayRef drop_front(unsigned N = 1) const { + assert(size() >= N && "Dropping more elements than exist"); + return slice(N, size() - N); + } + + /// \brief Drop the last \p N elements of the array. ArrayRef drop_back(unsigned N = 1) const { assert(size() >= N && "Dropping more elements than exist"); return slice(0, size() - N); @@ -285,7 +291,13 @@ namespace llvm { return MutableArrayRef(data()+N, M); } - MutableArrayRef drop_back(unsigned N) const { + /// \brief Drop the first \p N elements of the array. + MutableArrayRef drop_front(unsigned N = 1) const { + assert(this->size() >= N && "Dropping more elements than exist"); + return slice(N, this->size() - N); + } + + MutableArrayRef drop_back(unsigned N = 1) const { assert(this->size() >= N && "Dropping more elements than exist"); return slice(0, this->size() - N); } diff --git a/unittests/ADT/ArrayRefTest.cpp b/unittests/ADT/ArrayRefTest.cpp index 6cbadd6bc22..5a1ff785c34 100644 --- a/unittests/ADT/ArrayRefTest.cpp +++ b/unittests/ADT/ArrayRefTest.cpp @@ -67,6 +67,13 @@ TEST(ArrayRefTest, DropBack) { EXPECT_TRUE(AR1.drop_back().equals(AR2)); } +TEST(ArrayRefTest, DropFront) { + static const int TheNumbers[] = {4, 8, 15, 16, 23, 42}; + ArrayRef AR1(TheNumbers); + ArrayRef AR2(&TheNumbers[2], AR1.size() - 2); + EXPECT_TRUE(AR1.drop_front(2).equals(AR2)); +} + TEST(ArrayRefTest, Equals) { static const int A1[] = {1, 2, 3, 4, 5, 6, 7, 8}; ArrayRef AR1(A1);