How to efficiently copy std :: vector <char> to std :: string

Question

This question is the flip side of this How to efficiently copy std :: string to a vector

I usually copy the vector this way (a zero-terminated string)

std::string s((char*)&v[0]);

or (if the string is already declared), for example,

s = (char*)&v[0];

He is doing his job, but maybe there are better ways.

EDIT

C-style casts are ugly, I was told about it

s = reinterpret_cast<char*>(&vo[0]);

Answer 1

std::string s( &v[ 0 ] );

generates less than half the number of lines of assembly code in Visual C ++ 2005 as

std::string s( v.begin(), v.end() );

Answer 2

Just use the iterator constructor:

std::string s(v.begin(), v.end());

(): char -pointer-plus-size:

std::string s(v.data(), v.size());   // or &v[0]

, char* -constructor:

std::string s(v.data());             // or &v[0]

. @Dave , :

s.assign(v.begin(), v.end());
s.assign(v.data(), v.size());  // pointer plus size
s.assign(v.data());            // null-terminated

Answer 3

s.resize( v.size() );
std::copy( v.begin(), v.end(), s.begin() );

You can somehow ... because once these damned compilers understand the power of standardization, this method will be faster than any other ...

And a more serious note:

std::string( (char*)v.data(), v.size() );
s.assign( (char*)v.data(), v.size() );

... could be safer without loss of effectiveness.