Read whole ASCII file into C std string

Question

I need to load an entire file into memory and store it in a C++ std::string.

If I read it into a char[,] the answer is straightforward:

std::ifstream t;
int length;
t.open("file.txt");      // open input file
t.seekg(0, std::ios::end);    // go to the end
length = t.tellg();           // report location (this is the length)
t.seekg(0, std::ios::beg);    // go back to the beginning
buffer = new char[length];    // allocate memory for a buffer of appropriate dimension
t.read(buffer, length);       // read the whole file into the buffer
t.close();                    // close file handle

// ... Do stuff with buffer here ...

Now, I want to do the exact same thing, but using a std::string instead of a char[]. I want to avoid loops, i.e. I don't want to:

std::ifstream t;
t.open("file.txt");
std::string buffer;
std::string line;
while(t){
std::getline(t, line);
// ... Append line to buffer and go on
}
t.close()

Any ideas?