如何检测函数是否执行IO操作?

标准C++当然没有从USB中读取的功能,但是让我们暂时忽略它的细节。

函数执行“真实”I/O的问题可以在标准C++中通过询问库函数有哪些来近似。 observable side effects . 直接指向 Input/Output headers 现在当然还有 <filesystem> .

(从C++引用复制:)

<iosfwd>    forward declarations of all classes in the input/output library
<ios>       std::ios_base class, std::basic_ios class template and several typedefs
<istream>   std::basic_istream class template and several typedefs
<ostream>   std::basic_ostream, std::basic_iostream class templates and several typedefs
<iostream>  several standard stream objects
<fstream>   std::basic_fstream, std::basic_ifstream, std::basic_ofstream class templates and several typedefs
<sstream>   std::basic_stringstream, std::basic_istringstream, std::basic_ostringstream class templates and several typedefs
<syncstream> (since C++20)  std::basic_osyncstream, std::basic_syncbuf, and typedefs
<strstream> (deprecated)    std::strstream, std::istrstream, std::ostrstream
<iomanip>   Helper functions to control the format of input and output
<streambuf> std::basic_streambuf class template
<cstdio>    C-style input-output functions