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  1. #include <string>
  2. #include <iostream>
  3. #include <vector>
  4. #include <array>
  5.  
  6.  
  7. template<class e, class t, int N>
  8. std::basic_istream<e,t>& operator>>(std::basic_istream<e,t>& in, const e(&sliteral)[N]) {
  9.         std::array<e, N-1> buffer; //get buffer
  10.         in >> buffer[0]; //skips whitespace
  11.         if (N>2)
  12.                 in.read(&buffer[1], N-2); //read the rest
  13.         if (strncmp(&buffer[0], sliteral, N-1)) //if it failed
  14.                 in.setstate(in.rdstate() | std::ios::badbit); //set the state
  15.         return in;
  16. }
  17. template<class e, class t>
  18. std::basic_istream<e,t>& operator>>(std::basic_istream<e,t>& in, const e& cliteral) {
  19.         e buffer;  //get buffer
  20.         in >> buffer; //read data
  21.         if (buffer != cliteral) //if it failed
  22.                 in.setstate(in.rdstate() | std::ios::badbit); //set the state
  23.         return in;
  24. }
  25. template<class e, class t, int N>
  26. std::basic_istream<e,t>& operator>>(std::basic_istream<e,t>& in, e(&carray)[N]) {
  27.         return std::operator>>(in, carray);
  28. }
  29. template<class e, class t, class a>
  30. std::basic_istream<e,t>& operator>>(std::basic_istream<e,t>& in, a& obj) {
  31.         return in >> obj; //read data
  32. }
  33.  
  34.  
  35.  
  36. struct first {
  37.     std::string name;
  38.     double something;
  39. };
  40. struct mega {
  41.     std::vector<first> list;
  42. };
  43.  
  44. std::istream& operator>>(std::istream& file, first& obj) {
  45.     std::string symbol;
  46.     char equals;
  47.     while(file >> symbol) {
  48.         if (symbol[0] == '#') {
  49.             std::getline(file, symbol);
  50.         } else if (symbol == "<FIRST_END>") {
  51.             break;
  52.         } else if (symbol == "NAME") {
  53.             if (! (file>>'='>>obj.name) )
  54.                 std::cerr << symbol << " incorrectly formatted";
  55.         } else if (symbol == "SOMETHING") {
  56.             if (! (file>>'='>>obj.something) )
  57.                 std::cerr << symbol << " incorrectly formatted";
  58.         } else { //not a member: failure
  59.             std::cerr << symbol << " is not a member of first";
  60.             file.setstate(file.rdstate() | std::ios::badbit);
  61.             break;
  62.         }
  63.     }
  64.     return file;
  65. }
  66.  
  67. std::istream& operator>>(std::istream& file, mega& obj) {
  68.     std::string symbol;
  69.     first t;
  70.     while(file >> symbol) {
  71.         if (symbol[0] == '#') {
  72.             std::getline(file, symbol);
  73.         } else if (symbol == "<FIRST_BEGIN>") {
  74.             if (file >> t)
  75.                 obj.list.push_back(t);
  76.         } else {
  77.             std::cerr << symbol << " is not a member of mega";
  78.             file.setstate(file.rdstate() | std::ios::badbit);
  79.         }
  80.     }
  81.     return file;
  82. }
  83.  
  84. int main() {
  85.     mega obj;
  86.     std::cin >> obj;
  87.     std::cout << obj.list.size(); //1 if success
  88. }
Success #stdin #stdout 0s 3024KB
comments (?)
stdin
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<FIRST_BEGIN>
  NAME = myname
  SOMETHING = d
<FIRST_END>

<SECOND_BEGIN>
  INT = 5
  COMPLEX = 5.0 1.0
<SECOND_END>
stdout
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Standard output is empty
https://ideone.com/OyiB2
language:
C++14 (gcc 8.3)
created:
11 years ago
visibility:
public

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