C++ High Performance

Implementing the proxy

First, we'll create a proxy class representing the concatenation of two strings:

struct ConcatProxy { 
  const std::string& a; 
  const std::string& b; 
}; 

Then, we'll construct our own String class, simply consisting of std::string and an overloaded operator+ method. Note that this is an example of how to make and use proxy objects; creating your own String class is not something we recommend:

class String { 
public: 
  String() = default; 
  String(std::string istr) : str_{std::move(istr)}{} 
  std::string str_{};
}; 
 
auto operator+(const String& a, const String& b) {   return ConcatProxy{ a.str_, b.str_ };}

Here's a visual representation of the preceding code snippet:

Proxy object representing an accumulation of two strings

Lastly, ...