string constructor difference

[wolverine]

Hi

Could any one tell me the difference between these 2 string
constructors ?

1)string( const char* str );

2)string( const char* str, size_type length );

A reference
http://www.cppreference.com/cppstrin...structors.html says
that second one creates "a duplicate of str (optionally up to length
characters long)".Why is the word optionally used there. Does this mean
that if a '\0' appears in the character array the copying will
end there ?


Thanks
Kiran.

[Victor Bazarov]

Re: string constructor difference

wolverine wrote:

Could any one tell me the difference between these 2 string
constructors ?
>
1)string( const char* str );
>
2)string( const char* str, size_type length );
>
A reference
http://www.cppreference.com/cppstrin...structors.html says
that second one creates "a duplicate of str (optionally up to length
characters long)".Why is the word optionally used there.

Because the clowns who wrote this "reference" couldn't spring for one
extra description to separate the two constructors. BTW, in some of
those constructors there is also one more argument - the allocator.

Does this
mean that if a '\0' appears in the character array the copying will
end there ?

I don't know what this means. The constructor of the standard 'string'
class that has three arguments:

strint(char const* str, size_type n, Allocator const &a = Allocator())

will NOT stop if it encounters a null character. It will copy exactly
'n' characters from the array the first element of which is pointed to
by 'str'.

V
--
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I do not respond to top-posted replies, please don't ask

[wolverine]

Re: string constructor difference

Victor Bazarov wrote:

wolverine wrote:

Could any one tell me the difference between these 2 string
constructors ?

1)string( const char* str );

2)string( const char* str, size_type length );

A reference
http://www.cppreference.com/cppstrin...structors.html says
that second one creates "a duplicate of str (optionally up to length
characters long)".Why is the word optionally used there.

>
Because the clowns who wrote this "reference" couldn't spring for one
extra description to separate the two constructors. BTW, in some of
those constructors there is also one more argument - the allocator.
>

Does this
mean that if a '\0' appears in the character array the copying will
end there ?

>
I don't know what this means. The constructor of the standard 'string'
class that has three arguments:
>
strint(char const* str, size_type n, Allocator const &a = Allocator())
>
will NOT stop if it encounters a null character. It will copy exactly
'n' characters from the array the first element of which is pointed to
by 'str'.
>
V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

Thanks Victor.
Your answer cleared my doubt partially.