GNU C ++：unique_ptr.h没有这样的文件或目录

Question

I am cross compiling some code from Windows on Linux machine (Kubuntu 16.05),g++ 5.4.0 64bit. Using Code Lite IDE as a dev env. I have got several lines of code where I init unique pointer with

std::make_unique

The compiler complains with the error:

error: 'make_unique' is not a member of 'std'

I tried to add <memory> as well as <unique_ptr.h> to the header. Then the compiler complains that it can't find <unique_ptr.h> file. Interestingly,when I click to open the file from within the editor it is found and opened. The file is located in /usr/include/c++/5/bits/unique_ptr.h

I made sure that the compiler version that builds the code is indeed 5.4, so I don't understand why it doesn't support unique_ptr out of the box.I make sure to enable C++11 and C++14 flags:

-g;-O0;-std=c++14;-std=c++11;-Wall

Also, in the includes I add /user/include

What am I missing here? Do I have to include in the project the /usr/include/c++/5/bits/ directory explicitly?

Answer 1

Try these flags: -g -O0 -std=c++14 -Wall . Note that semicolon is not needed for separating flags.

Compiler will take the latest entry of -std so you are effectively compiling with C++11 but not C++14.

Answer 2

As you can see HERE enabling -std=c++11 after a newer standard disables the first declared standard. Enabling only C++14 is enough.

Answer 3

C++11 introduced std::unique_ptr , but there was no std::make_unique (this broke the "symmetry" of shared_ptr / make_shared ).

They fixed that in C++14 , adding std::make_unique .

So, if you compile your code in C++11 mode, you can't use std::make_unique .

As others already pointed out, you need to set the latest C++ standard with the -std compiler option; in this case, it's -std=c++14 to enable also std::make_unique .