Warn about do nothing expressions?

[Timon Gehr]

On 03/29/2014 05:31 PM, Frustrated wrote:
> .. i++, even in an assignment, increments i.
> ...

TDPL specifies the behaviour of i++ as follows:

{auto tmp=i; ++i; return tmp;}();

> i = j++;
> ...

i = {auto tmp=i; ++j; return tmp;}();

> even if i is assigned the previous value of j, j STILL gets incremented
> by one.
>
> Change i to j and it will work out.
> ...

i = {auto tmp=i; ++i; return tmp;}();