Comparison between distinct pointer types 'QString*' and 'const char*' lacks a cast [-fpermissive]

Imhotep

I had a QString inizialized in the .h file

@
QString *str;
@

In the .cpp constructor, str id declared

@
active = new QString;
if (str->isEmpty()) { *str = "foobar"; }
@

Now, when I try to set an int variable in this way

@
int num = (str == "foobar") ? 5: 6;
@

Qt Creator sends me this error:

"comparison between distinct pointer types 'QString*' and 'const char*' lacks a cast [-fpermissive]"

I guess that I have not run a cast, but what exactly?
Could you help me?

p3c0

Hi,

You should dereference str using * operator during comparison.
This will work,
@
int num = (*str == "foobar") ? 5: 6;
@

Imhotep

[quote author="p3c0" date="1404907893"]Hi,

You should dereference str using * operator during comparison.
This will work,
@
int num = (*str == "foobar") ? 5: 6;
@[/quote]

The program crash on start

p3c0

In your first post i see you have initialised active but not str. Is that a typo ?

Imhotep

No, i misswrited the variable name. str is correct

p3c0

So is it still crashing after initialising str ? I mean after doing this,
@
QString *str = new QString;
if (str->isEmpty()) { *str = "foobar"; }
int num = (*str == "foobar") ? 5: 6;
@

Imhotep

[quote author="p3c0" date="1404908755"]So is it still crashing after initialising str ? I mean after doing this,
@
QString *str = new QString;
if (str->isEmpty()) { *str = "foobar"; }
int num = (*str == "foobar") ? 5: 6;
@[/quote]

Solved

p3c0

Good. You can mark the post as solved.

SGaist

Hi,

Out of curiosity, why are you using a pointer to a QString ?

Chastain

This post is deleted!