[STLExtras] Add distance() for ranges, pred_size(), and succ_size()

This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecessors(BB))`, this
also introduces `pred_size()` and `succ_size()` helpers to make that
easier to write.

Differential Revision: https://reviews.llvm.org/D46668

llvm-svn: 332057

1 files changed, 3 insertions, 4 deletions

diff --git a/llvm/unittests/IR/BasicBlockTest.cpp b/llvm/unittests/IR/BasicBlockTest.cpp
index 07ed997f638..bdb2b8751ee 100644
--- a/llvm/unittests/IR/BasicBlockTest.cpp
+++ b/llvm/unittests/IR/BasicBlockTest.cpp
@@ -73,9 +73,9 @@ TEST(BasicBlockTest, PhiRange) {
   auto isPhi = [](Instruction &I) { return isa<PHINode>(&I); };
   auto Phis = make_filter_range(*BB, isPhi);
   auto ReversedPhis = reverse(make_filter_range(*BB, isPhi));
-  EXPECT_EQ(std::distance(Phis.begin(), Phis.end()), 3);
+  EXPECT_EQ(distance(Phis), 3);
   EXPECT_EQ(&*Phis.begin(), P1);
-  EXPECT_EQ(std::distance(ReversedPhis.begin(), ReversedPhis.end()), 3);
+  EXPECT_EQ(distance(ReversedPhis), 3);
   EXPECT_EQ(&*ReversedPhis.begin(), P3);
 
   // And iterate a const range.
@@ -87,8 +87,7 @@ TEST(BasicBlockTest, PhiRange) {
 }
 
 #define CHECK_ITERATORS(Range1, Range2)                                        \
-  EXPECT_EQ(std::distance(Range1.begin(), Range1.end()),                       \
-            std::distance(Range2.begin(), Range2.end()));                      \
+  EXPECT_EQ(distance(Range1), distance(Range2));                               \
   for (auto Pair : zip(Range1, Range2))                                        \
     EXPECT_EQ(&std::get<0>(Pair), std::get<1>(Pair));