Suppose s is
a b c
const std::string s =
std::cout << R"( s )" << std::endl;
How to std::cout the content of the string in raw literal? I mean the cout return the value in this format: "anbnc".
I need to transform a very large text into a std::string.
I cant use fileread as i need to define its value inside the src.
Answer
You can load this text file into a std::string like this:
Store the text in your file, e.g. mystring.txt, as a raw string literal in the format R"(raw_characters)":
R"(Run.M128A XmmRegisters[16];
BYTE Reserved4[96];", Run.CONTEXT64 := " DWORD64 P1Home;
DWORD64 P2Home;
...
)"
#include the file into a string:
namespace
{
const std::string mystring =
#include "mystring.txt"
;
}
Your IDE might flag this up as a syntax error, but it isn’t. What you’re doing is loading the contents of file directly into the string at compile time.
Finally print the string:
std::cout << mystring << std::endl;
Why not just save the escaped version of the string in the file?
Any way, here’s a function to ‘escape’ characters:
#include <iostream>
#include <string>
#include <unordered_map>
std::string replace_all(const std::string &mystring)
{
const std::unordered_map<char, std::string> lookup =
{ {'n', "\n"}, {'t', "\t"}, {'"', "\""} };
std::string new_string;
new_string.reserve(mystring.length() * 2);
for (auto c : mystring)
{
auto it = lookup.find(c);
if (it != lookup.end())
new_string += it->second;
else
new_string += c;
}
return new_string;
}
int main() {
std::string mystring = R"(Run.M128A XmmRegisters[16];
BYTE Reserved4[96];", Run.CONTEXT64 := " DWORD64 P1Home;
DWORD64 P2Home;
DWORD64 P3Home;
DWORD64 P4Home;
DWORD64 P5Home;
DWORD64 P6Home;)";
auto new_string = replace_all(mystring);
std::cout << new_string << std::endl;
return 0;
}
Here’s a demo.