Replace size() with empty() whenever possible

Before C++11, std::list's implementation of size was O(n). It should be
all O(1) now, but it is probably still a good idea to use empty() to
emphasize the intend.

1 files changed, 3 insertions, 3 deletions

diff --git a/src/mbgl/renderer/frame_history.cpp b/src/mbgl/renderer/frame_history.cpp
index 73336c029f..c95e82631e 100644
--- a/src/mbgl/renderer/frame_history.cpp
+++ b/src/mbgl/renderer/frame_history.cpp
@@ -5,18 +5,18 @@ using namespace mbgl;
 // Record frame history that will be used to calculate fading params
 void FrameHistory::record(const TimePoint& now, float zoom) {
     // first frame ever
-    if (!history.size()) {
+    if (history.empty()) {
         history.emplace_back(FrameSnapshot{TimePoint::min(), zoom});
         history.emplace_back(FrameSnapshot{TimePoint::min(), zoom});
     }
 
-    if (history.size() > 0 || history.back().z != zoom) {
+    if (!history.empty() || history.back().z != zoom) {
         history.emplace_back(FrameSnapshot{now, zoom});
     }
 }
 
 bool FrameHistory::needsAnimation(const Duration& duration) const {
-    if (!history.size()) {
+    if (history.empty()) {
         return false;
     }