A language development environment often comes with a language library, which is a wrapper around the operating system's API. We also call these language libraries a runtime library.

For the MSVC runtime library (CRT), according to the static / dynamic link, can be divided into static version and dynamic version; according to debugging / release, can be divided into debug version and release version; according to single thread / multi-thread, can be divided into single thread Version and multi-threaded version (but currently no single-threaded version is available in VS)

In debug mode, use the debug runtime: multithreaded debugging (/MTd), multithreaded debugging DLL (/MDd)

In release mode, use the release runtime: multithreaded (/MT), multithreaded DLL (/MD)

Run the library with debug d in debug mode, but the release mode does not. The difference between debugging and publishing is that the publishing mode omits the debugging information of the program. Simply put, the content for debugging in the debugging mode is deleted, so in general, the size of the executable file generated in the publishing mode is smaller than the debugging mode. Under the generation is small

Static linking: multi-threaded (/MT), multi-threaded debugging (/MTd)

Dynamic linking: multi-threaded DLL (/MD), multi-threaded debugging DLL (/MDd)

The dynamic link is D and the static link is T. The difference between the two is that the static link integrates the runtime library that the program depends on into the executable file, and the executable file no longer needs to run the runtime; the dynamic link does not integrate the runtime library that the program depends on into the executable file. The runtime is required to run the executable. Since the static link integrates the runtime that the program depends on into the executable file, in general, the size of the generated executable file is larger than that generated by the dynamic link.

The selection of these four runtimes in the VS project properties - "C / C + + -" code generation - "running library:

 

Instance

Source code:

1.  

2. #include <iostream>

3. using namespace std;

4.  

5. int main()

6. {

7. cout << "Hello World!" << endl;

8. system("pause");

9. return 0;

10. }

(The following experiments were completed under Win10+VS2017)

Win32, debug mode:

Win32, release mode:

We can find that in the same mode, the dynamic link is smaller than the static link; under the same kind of link, the release mode is smaller than the debug mode.

In x64, debug mode:

In x64, release mode:

Under the same mode and link, the executable file size generated under x64 is larger than that generated under Win32.