从文本文件中读取在c ++中

Question

I am writing a program that takes a single input line consisting of a pattern and the name of a text file. The program will then search the given text file for the given pattern.

I take the input and convert it into two strings: pattern and file_name I get an error on the following line:

ifstream text(file_name);

When I change it to the following, it compiles fine.

ifstream text("file_name");

Obviously, this is not what I want though since the file name must be determined by the user's input.

How can I make this compile given a changing file name?

Answer 1

For C++03, ifstream takes const char* parameter, you could try:

ifstream text(file_name.c_str());

While with C++11, your first statement should work.