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Binary File Reading Optimization
To optimally read binary files into a vector of unsigned chars, consider the following strategies:
Method 1: Custom Vector Construction
<code class="cpp">std::vector<BYTE> readFile(const char* filename) { std::ifstream file(filename, std::ios::binary); std::streampos fileSize = file.tellg(); file.seekg(0, std::ios::beg); std::vector<BYTE> fileData(fileSize); file.read((char*) &fileData[0], fileSize); return fileData; }</code>
This method explicitly creates a vector with the correct size based on file size. However, it casts the vector's data to char*, which is undesirable.
Method 2: Istreambuf Iterator
<code class="cpp">std::vector<BYTE> readFile(const char* filename) { std::ifstream file(filename, std::ios::binary); return std::vector<BYTE>((std::istreambuf_iterator<char>(file)), std::istreambuf_iterator<char>()); }</code>
This method uses an iterator that reads data into a char buffer internally. Although it is shorter, it still requires char iterators despite reading unsigned chars.
Method 3: Basic Ifstream Specialization
<code class="cpp">std::vector<BYTE> readFile(const char* filename) { std::basic_ifstream<BYTE> file(filename, std::ios::binary); return std::vector<BYTE>((std::istreambuf_iterator<BYTE>(file)), std::istreambuf_iterator<BYTE>()); }</code>
This method uses a specialized input file stream for unsigned chars. However, it may not be appropriate for all cases.
Optimizations
Considerations
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