Re: Lambda testcase fails when optimization enabled in gcc and llvm

From: Peter Dimov (pdimov_at_[hidden])
Date: 2019-07-19 11:03:09

navya deepika garakapati wrote:

> Hi Devs,
> consider below reduced testcase from boost lamda.
>
> $cat result_of_tests.cpp
>
> #include <boost/lambda/lambda.hpp>
> #include <stdio.h>
> template<class A, class F> typename boost::result_of<F(A)>::type apply1(F 
> f, A b) {
>     return f(b);
> }
> using namespace boost::lambda;
> int main(int, char *[]) {
>     int one = 1;
>     int d= (apply1<int>(_1 ,one) == 1);
>     printf("\n%d\n",d);
>     return 0;
> }

f(b) returns a reference to b, which goes out of scope at the closing brace; 
the example has undefined behavior. You should report this as an issue at 
https://github.com/boostorg/lambda/issues.