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c++functionobjectcalltemporary

C++ Call function of a temporary object

For example:

private:
    std::vector<std::string> _content;
public:
    Document (const std::string& path) :_content(FileIO().read(path)) { }

Is it OK to call a function ( read() ) directly with an "temporary" Object ( FileIO() ) ? I'm asking because it seems very convenient, but I have never seen code like this before. Just want to know if this is "valid" C++ code, rather than some weird anti pattern or performance "no no".

Solution

  • It's fine. path is well-defined, and the anonymous temporary will be valid during initialisation of the member _content.

    You should note that if an exception is thrown by FileIO().read(path) then ~Document() will not be called.