MinGW g++: Multiple definition of vsnprintf when using to_string

Question

I just started using MinGW for Windows. When trying to create executable using

g++ a.cpp -o a.exe -std=c++14

for the code below:

Answer 1

Installing MinGW packages mingw32-libmingwex-* will link an appropriate version of vsnprintf and avoid the linker error.

Answer 2

This issue, i.e. multiple definition of vsnprintf, still exists in MinGW as December 2019.

After investigating a lot, I found the solution in the official mailing list.

It's a bug in mingwrt-5.2.2. Downgrading to the mingwrt-5.2.1 version solves that issue. To do that, just input the following command:

mingw-get upgrade mingwrt=5.2.1

Then restart the MinGW shell.

Read the full story here.

Note: MinGW-w64 and MinGW are separate projects, so the accepted solution is not so helpful to me, as I want to keep MinGW and not to move to MinGW-w64.

Answer 3

There are multiple definitions of vsnprintf in both stdio.h and libmingwex.a. I am able to work this around by adding #define __USE_MINGW_ANSI_STDIO 0 to the start of the code, before any includes, which disables the definition of vsnprintf in stdio.h.

Answer 4

I solved this issue using MinGW w64 compiler

1. download mingw-w64-install.exe
2. setup to Version: 6.3.0, Architecture: i686, Threads: posix, Exception: dwarf and Build revision: 2.

I hope this will be of some help.