Use implicit_cast<> instead of static_cast<> whenever possible

util/file/file_writer.cc

Index: util/file/file_writer.cc
diff --git a/util/file/file_writer.cc b/util/file/file_writer.cc
index 5c7c25dc46dd1a797115882cc6322e8a4bc6da0a..2a3d7c404058e16f31e7776e76e4705f251f81bf 100644
--- a/util/file/file_writer.cc
+++ b/util/file/file_writer.cc
@@ -93,7 +93,7 @@ bool FileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
 
   while (size > 0) {
     size_t writev_iovec_count =
-        std::min(remaining_iovecs, static_cast<size_t>(IOV_MAX));
+        std::min(remaining_iovecs, implicit_cast<size_t>(IOV_MAX));
     ssize_t written = HANDLE_EINTR(writev(fd_.get(), iov, writev_iovec_count));
     if (written < 0) {
       PLOG(ERROR) << "writev";
@@ -113,7 +113,7 @@ bool FileWriter::WriteIoVec(std::vector<WritableIoVec>* iovecs) {
 
     while (written > 0) {
       size_t wrote_this_iovec =
-          std::min(static_cast<size_t>(written), iov->iov_len);
+          std::min(implicit_cast<size_t>(written), iov->iov_len);
       written -= wrote_this_iovec;
       if (wrote_this_iovec < iov->iov_len) {
         iov->iov_base =