[FIX] preserving parens for std::cout expressions

[filipsajdak]

There is a bug in expressions inside std::cout shift expressions. The example is in regression-tests/mixed-test-parens.cpp2

The code:

std::cout << (1+2)*(3+v[0]);

currently compiles to

std::cout << (1+2)* 3+v[0];

After this change the cppfront preserves the parens and returns:

std::cout << (1+2)*(3+v[0]);

This PR closes #91

[filipsajdak]

Probably we need to check if there is more expressions that might suffer from disappearing parens.

[hsutter]

Thanks, this looks reasonable. I'm slightly confused because I remember that these parens were correctly emitted (for the first time) with a commit about a week ago. Curious what caused the regression?

[filipsajdak]

@hsutter it looks like this test case was broken by my previous PR about parens #67 (that one you refers to). It looks like everything works fine before it. Sorry, my mistake I should have run more regression tests. I already do it before sending PRs (that is why I found this issue).

Previous PR fixes different scenario:

f((i+(i+1)*2)/2);

I will investigate it a little more later.

[JohelEGP]

The issue had been known since #81. From the CI run:

       Start  72: codegen/check/mixed-test-parens
85/118 Test  #72: codegen/check/mixed-test-parens ................................................***Failed    0.00 sec