problem about lambda.

[lays]

I am learning Lambda expression, why the output is still 7.
It seems the lambda hasn't change the value.

int x=7;
[&x](){x=5;};
cout << x;
cin.get();

My implementation is vs2010. Could it be the vs2010 doesn't support c++11 quite well?

[Lachlan Easton]

You haven't called the lambda, only defined it. You can either put the lambda in a variable and call it from there

auto Lamb = [&x](){x=5;};
Lamb();

or call the lambda in place [&x](){x=5;}(); (note the extra parentheses "()" call the lambda)

[Catfish666]

lays wrote:

Could it be the vs2010 doesn't support c++11 quite well?

Yes. You should upgrade to Visual Studio 2013.
http://www.visualstudio.com/en-us/products/visual-studio-express-vs.aspx

Edit: you are defining the lambda function but you are not using it.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

#include <iostream> int main() { int x = 7; auto my_lambda = [&x]() { x = 5; }; my_lambda(); std::cout << x; std::cin.get(); }

5

[lays]

thx alot.