I am trying to run a simple lambda example.
// lambda.cpp
#include <functional>
//#include <tr1/functional>
int main()
{
// Assign the same lambda expression to a function object.
function<int (int, int)> f2 = [] (int x, int y) { return x + y; };
//function<int (int, int)> f2 = [] (int x, int y) { return x + y; };
}
I'm compiling it like this:
$ g++ -std=c++0开发者_C百科x -fpermissive lamdas.cpp
lambdas.cpp: In function ‘int main()’:
lambdas.cpp:10: error: expected primary-expression before ‘=’ token
lambdas.cpp:10: error: expected primary-expression before ‘[’ token
lambdas.cpp:10: error: expected primary-expression before ‘]’ token
lambdas.cpp:10: error: expected primary-expression before ‘int’
lambdas.cpp:10: error: expected primary-expression before ‘int’
lambdas.cpp:10: error: expected ‘;’ before ‘{’ token
How do I get it to compile with no errors?
Did you mean std::function
?
Standard library features live in the std
namespace.
It's also interesting that your copy/paste is clearly fake; you wrote "lamdas.cpp" then compiled "lambdas.cpp"!
std::function<int (int, int)> f2 = [] (int x, int y) { return x + y; };
or, probably better
auto f2 = [] (int x, int y) { return x + y; };
It looks to me like you forgot -std=c++0x.
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