Prefer copy_n and fill_n over copy and fill where appropriate.

This lets us avoid having to do the addition manually.

3 files changed, 7 insertions, 6 deletions

diff --git a/absl/strings/escaping.cc b/absl/strings/escaping.cc
index 2827fbaa..6103750a 100644
--- a/absl/strings/escaping.cc
+++ b/absl/strings/escaping.cc
@@ -846,9 +846,10 @@ void HexStringToBytesInternal(const char* from, T to, size_t num) {
 template <typename T>
 void BytesToHexStringInternal(const unsigned char* src, T dest, size_t num) {
   auto dest_ptr = &dest[0];
-  for (auto src_ptr = src; src_ptr != (src + num); ++src_ptr, dest_ptr += 2) {
+  for (auto src_ptr = src; src_ptr != (src + num); ++src_ptr) {
     const char* hex_p = &numbers_internal::kHexTable[*src_ptr * 2];
-    std::copy(hex_p, hex_p + 2, dest_ptr);
+    *dest_ptr++ = *hex_p++;
+    *dest_ptr++ = *hex_p;
   }
 }
 
diff --git a/absl/strings/internal/charconv_bigint.cc b/absl/strings/internal/charconv_bigint.cc
index 282b639e..552fecc6 100644
--- a/absl/strings/internal/charconv_bigint.cc
+++ b/absl/strings/internal/charconv_bigint.cc
@@ -296,9 +296,9 @@ template <int max_words>
         std::min(n / kLargePowerOfFiveStep, kLargestPowerOfFiveIndex);
     if (first_pass) {
       // just copy, rather than multiplying by 1
-      std::copy(
+      std::copy_n(
           LargePowerOfFiveData(big_power),
-          LargePowerOfFiveData(big_power) + LargePowerOfFiveSize(big_power),
+          LargePowerOfFiveSize(big_power),
           answer.words_);
       answer.size_ = LargePowerOfFiveSize(big_power);
       first_pass = false;
diff --git a/absl/strings/internal/charconv_bigint.h b/absl/strings/internal/charconv_bigint.h
index 8f702976..d8992386 100644
--- a/absl/strings/internal/charconv_bigint.h
+++ b/absl/strings/internal/charconv_bigint.h
@@ -121,7 +121,7 @@ class BigUnsigned {
           ++size_;
         }
       }
-      std::fill(words_, words_ + word_shift, 0u);
+      std::fill_n(words_, word_shift, 0u);
     }
   }
 
@@ -197,7 +197,7 @@ class BigUnsigned {
   }
 
   void SetToZero() {
-    std::fill(words_, words_ + size_, 0u);
+    std::fill_n(words_, size_, 0u);
     size_ = 0;
   }