error C2040: 'std::string' differs in levels of indirection from'const char *'

[newbarker]

Hello,

This program doesn't work and provides me the errror message "error
C2040: 'p' : 'std::string' differs in levels of indirection from
'const char *'":

#include <string>

int main()
{
const char* p = "fred";
std::string(p);

return 0;
}

This version DOES work:

#include <string>

int main()
{
const char* p = "fred";
std::string named(p);

return 0;
}

Can someone explain why the first program doesn't compile? Aren't I
just creating a temporary std::string object initialised from p?

Regards,

Pete

[peter koch]

On 19 Aug., 19:02, newbar...@gmail .com wrote:

Hello,

This program doesn't work and provides me the errror message "error
C2040: 'p' : 'std::string' differs in levels of indirection from
'const char *'":

#include <string>

int main()
{
* * * * const char* p = "fred";
* * * * std::string(p);

* * * * return 0;

}

This version DOES work:

#include <string>

int main()
{
* * * * const char* p = "fred";
* * * * std::string named(p);

* * * * return 0;

}

Can someone explain why the first program doesn't compile? Aren't I
just creating a temporary std::string object initialised from p?

No. std::string(p); is the same statement as std::string p; -
parenthesis are allowed in a declaration.

/Peter

[Juha Nieminen]

peter koch wrote:

No. std::string(p); is the same statement as std::string p; -
parenthesis are allowed in a declaration.

You can get around the problem by writing: (std::string)(p );

[puzzlecracker]

On Aug 19, 1:02 pm, newbar...@gmail .com wrote:

Hello,

This program doesn't work and provides me the errror message "error
C2040: 'p' : 'std::string' differs in levels of indirection from
'const char *'":

#include <string>

int main()
{
const char* p = "fred";
std::string(p);

return 0;

}

This version DOES work:

#include <string>

int main()
{
const char* p = "fred";
std::string named(p);

return 0;

}

Can someone explain why the first program doesn't compile? Aren't I
just creating a temporary std::string object initialised from p?

Regards,

Pete

I think the problem is with the compiler since string class contains
a ctor that takes const char * argument.

[newbarker]

On 20 Aug, 03:42, puzzlecracker <ironsel2...@gm ail.comwrote:

On Aug 19, 1:02 pm, newbar...@gmail .com wrote:

Hello,

This program doesn't work and provides me the errror message "error
C2040: 'p' : 'std::string' differs in levels of indirection from
'const char *'":

#include <string>

int main()
{
* * * * const char* p = "fred";
* * * * std::string(p);

* * * * return 0;

}

This version DOES work:

#include <string>

int main()
{
* * * * const char* p = "fred";
* * * * std::string named(p);

* * * * return 0;

}

Can someone explain why the first program doesn't compile? Aren't I
just creating a temporary std::string object initialised from p?

Regards,

Pete

I think the problem is with the compiler since string class contains
a ctor that takes const char * argument.- Hide quoted text -

- Show quoted text -

I'm glad to hear that. I was wondering if there's something missing in
my knowledge of C++ in this area but as the following compiles, I
don't think so:

const char* p = "fred";
std::string s = std::string(p);

I'm using VC++ .NET 2003 V7.1.

[Ian Collins]

puzzlecracker wrote:

On Aug 19, 1:02 pm, newbar...@gmail .com wrote:

>Hello,

This program doesn't work and provides me the errror message "error
C2040: 'p' : 'std::string' differs in levels of indirection from
'const char *'":

#include <string>

int main()
{
const char* p = "fred";
std::string(p);

return 0;

}

I think the problem is with the compiler since string class contains
a ctor that takes const char * argument.

No, that is not correct.

Read Peter's answer carefully.

The first example is identical to

const char* p = "fred";
std::string p;

It's a simple multiple redeclaration error. The compiler error is less
than helpful.

--
Ian Collins.

[puzzlecracker]

On Aug 20, 5:11*am, Ian Collins <[e-mail] mwrote:

puzzlecracker wrote:

On Aug 19, 1:02 pm, newbar...@gmail .com wrote:

Hello,

This program doesn't work and provides me the errror message "error
C2040: 'p' : 'std::string' differs in levels of indirection from
'const char *'":

#include <string>

int main()
{
* * * * const char* p = "fred";
* * * * std::string(p);

* * * * return 0;

}

I think the problem is with the compiler since string class contains
a ctor that takes const char * argument.

No, that is not correct.

Read Peter's answer carefully.

The first example is identical to

const char* p = "fred";
std::string p;

It's a simple multiple redeclaration error. *The compiler error is less
than helpful.

--
Ian Collins.

Thanks, I didn't notice that....