update: fully qualified in std namespace

src/impl/sine.inc

@@ -35,13 +35,13 @@ constexpr double sin_core(double x) {
 
 /// Calculate the sin(x) value in radians.
 constexpr double sin(double x) {
-    x = std::fmod(x, 2 * PI); // -2PI < x < 2PI
+    x = ::std::fmod(x, 2 * PI); // -2PI < x < 2PI
 
-    if (std::abs(x) > PI) {
+    if (::std::abs(x) > PI) {
         x -= ((x > 0) ? 2 : -2) * PI; // -PI < x < PI
     }
 
-    if (std::abs(x) > PI / 2) {
+    if (::std::abs(x) > PI / 2) {
         x = ((x > 0) ? 1 : -1) * PI - x; // -PI / 2 < x < PI / 2
     }
     return sin_core(x); // closer to 0 for better accuracy

src/impl/wrapper.cc

@@ -18,13 +18,13 @@ std::string MD5::Digest() const {
 MD5& MD5::Update(const void *data, uint64_t len) {
     if (buffer_size_ != 0) {
         if (buffer_size_ + len < 64) { // buffer not filled
-            std::memcpy(buffer_ + buffer_size_, data, len);
+            ::std::memcpy(buffer_ + buffer_size_, data, len);
             buffer_size_ += len;
             return *this; // save into buffer and return
         }
 
         auto size = 64 - buffer_size_;
-        std::memcpy(buffer_ + buffer_size_, data, size);
+        ::std::memcpy(buffer_ + buffer_size_, data, size);
         UpdateImpl(buffer_, 64); // fill and update with buffer
         data = static_cast<const char*>(data) + size;
         buffer_size_ = 0;
@@ -34,7 +34,7 @@ MD5& MD5::Update(const void *data, uint64_t len) {
     data = UpdateImpl(data, len);
     len &= 0b111111; // len -> [0, 64)
     if (len != 0) {
-        std::memcpy(buffer_, data, len); // save remain data into buffer
+        ::std::memcpy(buffer_, data, len); // save remain data into buffer
         buffer_size_ = len;
     }
     return *this;