什么是C++中的文件映射？

#include <windows.h>
#include <iostream>

int main() {
    // 创建文件映射
    HANDLE hFile = CreateFile(L"example.txt", GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
    if (hFile == INVALID_HANDLE_VALUE) {
        std::cerr << "Failed to open file" << std::endl;
        return 1;
    }

    HANDLE hMapFile = CreateFileMapping(hFile, NULL, PAGE_READWRITE, 0, 1024, L"MyFileMapping");
    if (hMapFile == NULL) {
        std::cerr << "Failed to create file mapping" << std::endl;
        CloseHandle(hFile);
        return 1;
    }

    // 映射视图
    LPVOID pView = MapViewOfFile(hMapFile, FILE_MAP_ALL_ACCESS, 0, 0, 0);
    if (pView == NULL) {
        std::cerr << "Failed to map view of file" << std::endl;
        CloseHandle(hMapFile);
        CloseHandle(hFile);
        return 1;
    }

    // 写入数据
    char* data = (char*)pView;
    strcpy(data, "Hello, File Mapping!");

    // 读取数据
    std::cout << "Data: " << data << std::endl;

    // 释放资源
    UnmapViewOfFile(pView);
    CloseHandle(hMapFile);
    CloseHandle(hFile);

    return 0;
}