Converting a C-style string to a C++ std::string

c++ string cstring
Ian Burris picture Ian Burris · Jan 22, 2011 · Viewed 88.8k times · Source

What is the best way to convert a C-style string to a C++ std::string? In the past I've done it using stringstreams. Is there a better way?

Answer

templatetypedef picture templatetypedef · Jan 22, 2011

C++ strings have a constructor that lets you construct a std::string directly from a C-style string:

const char* myStr = "This is a C string!";
std::string myCppString = myStr;

Or, alternatively:

std::string myCppString = "This is a C string!";

As @TrevorHickey notes in the comments, be careful to make sure that the pointer you're initializing the std::string with isn't a null pointer. If it is, the above code leads to undefined behavior. Then again, if you have a null pointer, one could argue that you don't even have a string at all. :-)

Related questions

How is std::string implemented?

I am curious to know how std::string is implemented and how does it differ from c string?If the standard does not specify any implementation then any implementation with explanation would be great with how it satisfies the string …

Read More
How can I hash a string to an int using c++?

I have to write my own hash function. If I wanted to just make the simple hash function that maps each letter in the string to a numerical value (i.e. a=1, b=2, c=3, ...), is there a way I can …

Read More
What is std::string::c_str() lifetime?

In one of my programs, I have to interface with some legacy code that works with const char*. Lets say I have a structure which looks like: struct Foo { const char* server; const char* name; }; My higher-level application only deals …

Read More