Simplify `std::copy` with `std::copy_n`

+ a surprise `std::memcpy` in VolumeVerifier.cpp.

Source/Core/Core/FifoPlayer/FifoRecorder.cpp

@@ -382,7 +382,7 @@ void FifoRecorder::UseMemory(u32 address, u32 size, MemoryUpdate::Type type, boo
     memUpdate.fifoPosition = (u32)(m_FifoData.size());
     memUpdate.type = type;
     memUpdate.data.resize(size);
-    std::copy(newData, newData + size, memUpdate.data.begin());
+    std::copy_n(newData, size, memUpdate.data.begin());
 
     m_CurrentFrame.memoryUpdates.push_back(std::move(memUpdate));
   }

Source/Core/Core/HW/GBACore.cpp

@@ -543,8 +543,7 @@ void Core::RunCommand(Command& command)
     {
       int recvd = GBASIOJOYSendCommand(
           &m_sio_driver, static_cast<GBASIOJOYCommand>(command.buffer[0]), &command.buffer[1]);
-      std::copy(command.buffer.begin() + 1, command.buffer.begin() + 1 + recvd,
+      std::copy_n(command.buffer.begin() + 1, recvd, std::back_inserter(m_response));
-                std::back_inserter(m_response));
     }
 
     if (m_thread && !m_response_ready)

Source/Core/Core/HW/WiimoteReal/IOWin.cpp

@@ -275,7 +275,7 @@ int IOWritePerWriteFile(HANDLE& dev_handle, OVERLAPPED& hid_overlap_write,
   // This is currently needed by the Toshiba Bluetooth Stack.
   if ((write_method == WWM_WRITE_FILE_LARGEST_REPORT_SIZE) && (MAX_PAYLOAD > len))
   {
-    std::copy(buf, buf + len, resized_buffer);
+    std::copy_n(buf, len, resized_buffer);
     std::fill(resized_buffer + len, resized_buffer + MAX_PAYLOAD, 0);
     write_buffer = resized_buffer + 1;
     bytes_to_write = MAX_PAYLOAD - 1;

Source/Core/Core/IOS/USB/Bluetooth/BTEmu.cpp

@@ -413,7 +413,7 @@ void BluetoothEmuDevice::ACLPool::Store(const u8* data, const u16 size, const u1
   m_queue.push_back(Packet());
   auto& packet = m_queue.back();
 
-  std::copy(data, data + size, packet.data);
+  std::copy_n(data, size, packet.data);
   packet.size = size;
   packet.conn_handle = conn_handle;
 }
@@ -438,7 +438,7 @@ void BluetoothEmuDevice::ACLPool::WriteToEndpoint(const USB::V0BulkMessage& endp
   header->length = size;
 
   // Write the packet to the buffer
-  std::copy(data, data + size, (u8*)header + sizeof(hci_acldata_hdr_t));
+  std::copy_n(data, size, (u8*)header + sizeof(hci_acldata_hdr_t));
 
   m_queue.pop_front();
 

Source/Core/DiscIO/Blob.cpp

@@ -153,8 +153,7 @@ bool SectorReader::Read(u64 offset, u64 size, u8* out_ptr)
     u32 can_read = m_block_size * cache->num_blocks - read_offset;
     u32 was_read = static_cast<u32>(std::min<u64>(can_read, remain));
 
-    std::copy(cache->data.begin() + read_offset, cache->data.begin() + read_offset + was_read,
+    std::copy_n(cache->data.begin() + read_offset, was_read, out_ptr);
-              out_ptr);
 
     offset += was_read;
     out_ptr += was_read;

Source/Core/DiscIO/CompressedBlob.cpp

@@ -130,7 +130,7 @@ bool CompressedBlobReader::GetBlock(u64 block_num, u8* out_ptr)
 
   if (uncompressed)
   {
-    std::copy(m_zlib_buffer.begin(), m_zlib_buffer.begin() + comp_block_size, out_ptr);
+    std::copy_n(m_zlib_buffer.begin(), comp_block_size, out_ptr);
   }
   else
   {

Source/Core/DiscIO/DirectoryBlob.cpp

@@ -107,8 +107,7 @@ bool DiscContent::Read(u64* offset, u64* length, u8** buffer, DirectoryBlobReade
     else if (std::holds_alternative<ContentMemory>(m_content_source))
     {
       const auto& content = std::get<ContentMemory>(m_content_source);
-      std::copy(content->begin() + offset_in_content,
+      std::copy_n(content->begin() + offset_in_content, bytes_to_read, *buffer);
-                content->begin() + offset_in_content + bytes_to_read, *buffer);
     }
     else if (std::holds_alternative<ContentPartition>(m_content_source))
     {

Source/Core/DiscIO/LaggedFibonacciGenerator.cpp

@@ -78,8 +78,8 @@ bool LaggedFibonacciGenerator::GetSeed(const u32* data, size_t size, size_t data
   const size_t data_offset_mod_k = data_offset % LFG_K;
   const size_t data_offset_div_k = data_offset / LFG_K;
 
-  std::copy(data, data + LFG_K - data_offset_mod_k, lfg->m_buffer.data() + data_offset_mod_k);
+  std::copy_n(data, LFG_K - data_offset_mod_k, lfg->m_buffer.data() + data_offset_mod_k);
-  std::copy(data + LFG_K - data_offset_mod_k, data + LFG_K, lfg->m_buffer.data());
+  std::copy_n(data + LFG_K - data_offset_mod_k, data_offset_mod_k, lfg->m_buffer.data());
 
   lfg->Backward(0, data_offset_mod_k);
 

Source/Core/DiscIO/TGCBlob.cpp

@@ -28,8 +28,8 @@ void Replace(u64 offset, u64 size, u8* out_ptr, u64 replace_offset, u64 replace_
 
   if (replace_end > replace_start)
   {
-    std::copy(replace_ptr + (replace_start - replace_offset),
+    std::copy_n(replace_ptr + (replace_start - replace_offset), replace_end - replace_start,
-              replace_ptr + (replace_end - replace_offset), out_ptr + (replace_start - offset));
+                out_ptr + (replace_start - offset));
   }
 }
 

Source/Core/DiscIO/VolumeVerifier.cpp

@@ -1301,8 +1301,7 @@ void VolumeVerifier::Finish()
     {
       m_result.hashes.crc32 = std::vector<u8>(4);
       const u32 crc32_be = Common::swap32(m_crc32_context);
-      const u8* crc32_be_ptr = reinterpret_cast<const u8*>(&crc32_be);
+      std::memcpy(m_result.hashes.crc32.data(), &crc32_be, 4);
-      std::copy(crc32_be_ptr, crc32_be_ptr + 4, m_result.hashes.crc32.begin());
     }
 
     if (m_hashes_to_calculate.md5)

Source/Core/DiscIO/WIABlob.cpp

@@ -1635,7 +1635,7 @@ WIARVZFileReader<RVZ>::ProcessAndCompress(CompressThreadState* state, CompressPa
       const size_t size = state->compressor->GetSize();
 
       entry.main_data.resize(size);
-      std::copy(data, data + size, entry.main_data.data());
+      std::copy_n(data, size, entry.main_data.data());
 
       if (compressed_exception_lists)
         entry.exception_lists.clear();

Source/Core/UpdaterCommon/UpdaterCommon.cpp

@@ -3,6 +3,7 @@
 
 #include "UpdaterCommon/UpdaterCommon.h"
 
+#include <algorithm>
 #include <array>
 #include <memory>
 #include <optional>
@@ -150,7 +151,7 @@ Manifest::Hash ComputeHash(const std::string& contents)
                      false);
 
   Manifest::Hash out;
-  std::copy(full.begin(), full.begin() + 16, out.begin());
+  std::copy_n(full.begin(), 16, out.begin());
   return out;
 }