Does libstdc++ not implement std::stoi?

Question

I want to use std::stoi. Although I could use ::atoi(str.c_str()) it would make the code cleaner if this would work. But Eclipse tells me:

Function 'stoi' could not be resolved

I checked that

the header <string> is included,
include paths are set correctly, as I can use std::string,
the compiler flag -std=c++0x -std=c++11 is set too.

Is stoi() missing in gcc, or is it somehow my fault?

I am using gcc (Debian 4.7.2-4) 4.7.2.

You should probably have only `-std=c++11`. Can't imagine that would cause this bug though. (Also, just to confirm, you are either using `std::stoi` or pulling in the std namespace?) Wait.... Will it compile? Like Nikos C. said below, it might just be Eclipse complaining. — Corbin, Nov 19 '12 at 12:27

score 17 · Accepted Answer · answered Nov 19 '12 at 12:29

17

You're using GCC 4.7.2, so std::stoi is supported. You can ignore the Eclipse warning. It should compile and run fine. The problem is with the Eclipse editor, not with GCC.

(You only need the -std=c++11 or -std=gnu++11 [to also get the GCC extensions] flag, btw. -std=c++0x is just a deprecated synonym.)

answered Nov 19 '12 at 12:29

Nikos C.

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``c++11`` and ``gnu++11`` are different. – Sergey K. Nov 19 '12 at 12:31
@SergeyK. I know. But both enable C++-11 support. – Nikos C. Nov 19 '12 at 12:32
Okay, yes your right. It compiles. Can I somehow do something aganist these Eclipse errors? – ManuelSchneid3r Nov 19 '12 at 12:35
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@DevNoob Maybe this helps: http://stackoverflow.com/questions/9131763/eclipse-cdt-c11-c0x-support – Nikos C. Nov 19 '12 at 12:36
+1 Hah, nice one. Try to compile it before taking *Eclipse*'s stupid complaints too serious. – Christian Rau Nov 19 '12 at 12:50

Eric B · Answer 2 · 2012-11-19T13:20:47.070

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You can get rid of the red squiggles in eclipse, (from here):

Project Properties->C/C++ General->Preprocessor Include Paths, Macros->[Providers] tab->your Built-in Compiler Settings provider (toolchain dependent). Click on "Workspace Settings" link which gets you to "Settings" property page, select [Discovery] tab and your provider again. There is "Command to get compiler specs", add "-std=c++11" in there.

hit apply and close everything, then index->rebuild and you should be all set.

Or, if your version of eclipse is older, you might just have to do this:

Project->Properties->C/C++ Build->Discovery Options->GCC C++ Compiler

and add the "-std=c++11" flag to the invocation arguments there. This is "deprecated" though, so you may want to consider updating Eclipse since you're updating your compiler too.

edited Nov 19 '12 at 13:20

answered Nov 19 '12 at 12:46

Eric B

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I read this in the eclipse FAQ, but the problem was, that it was not set permanent. It chnaged nothing and after reopening project settings the flag has dissapeared. – ManuelSchneid3r Nov 19 '12 at 12:50
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It fixed it permanently for me. You might have to close eclipse and re-open? – Eric B Nov 19 '12 at 13:17
Goddamn. okay its permanent. But `__GXX_EXPERIMENTAL_CXX0X__` solves the `stoi` problem. But raises a `vector.insert` problem. but your way does not solve `stoi` problem. Its horrible. – ManuelSchneid3r Nov 19 '12 at 16:00

Does libstdc++ not implement std::stoi?

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