fix compiler warnings from gcc-4.9 + -Wunused-variable

[folly.git] / folly / experimental / fibers / WhenN-inl.h

diff --git a/folly/experimental/fibers/WhenN-inl.h b/folly/experimental/fibers/WhenN-inl.h
index d931e16c4f4fe34fe69bc3c0c0640e12bf373e9b..dc1c67eb9e82dd3dc03c91f86bd607fcbc872199 100644 (file)
--- a/folly/experimental/fibers/WhenN-inl.h
+++ b/folly/experimental/fibers/WhenN-inl.h
@@ -37,7 +37,8 @@ collectN(InputIterator first, InputIterator last, size_t n) {
   typedef typename std::result_of<
     typename std::iterator_traits<InputIterator>::value_type()>::type Result;
   assert(n > 0);
-  assert(n <= std::distance(first, last));
+  assert(std::distance(first, last) >= 0);
+  assert(n <= static_cast<size_t>(std::distance(first, last)));
 
   struct Context {
     std::vector<std::pair<size_t, Result>> results;
@@ -98,7 +99,8 @@ typename std::enable_if<
     >::value, std::vector<size_t>>::type
 collectN(InputIterator first, InputIterator last, size_t n) {
   assert(n > 0);
-  assert(n <= std::distance(first, last));
+  assert(std::distance(first, last) >= 0);
+  assert(n <= static_cast<size_t>(std::distance(first, last)));
 
   struct Context {
     std::vector<size_t> taskIndices;