require.h

来自「很经典的书籍」· C头文件 代码 · 共 71 行

//: :require.h
// Test for error conditions in programs
// Local "using namespace std" for old compilers
#ifndef REQUIRE_H
#define REQUIRE_H
#include <cstdio>
#include <cstdlib>
#include <fstream>

inline void require(bool requirement,
  const char* msg = "Requirement failed") {
  using namespace std;
  if (!requirement) {
    fputs(msg, stderr);
    fputs("\n", stderr);
    exit(EXIT_FAILURE);
  }
}

inline void requireArgs(int argc, int args,
  const char* msg = "Must use %d arguments") {
  using namespace std;
   if (argc != args + 1) {
     fprintf(stderr, msg, args);
     fputs("\n", stderr);
     exit(EXIT_FAILURE);
   }
}

inline void requireMinArgs(int argc, int minArgs,
  const char* msg =
    "Must use at least %d arguments") {
  using namespace std;
  if(argc < minArgs + 1) {
    fprintf(stderr, msg, minArgs);
    fputs("\n", stderr);
    exit(EXIT_FAILURE);
  }
}

inline void assure(std::ifstream& in,
  const char* filename = "") {
  using namespace std;
  if(!in) {
    fprintf(stderr,
      "Could not open file %s\n", filename);
    exit(EXIT_FAILURE);
  }
}

inline void assure(std::ofstream& in,
  const char* filename = "") {
  using namespace std;
  if(!in) {
    fprintf(stderr,
      "Could not open file %s\n", filename);
    exit(EXIT_FAILURE);
  }
}

inline void assure(std::fstream& in,
  const char* filename = "") {
  using namespace std;
  if(!in) {
    fprintf(stderr,
      "Could not open file %s\n", filename);
    exit(EXIT_FAILURE);
  }
}
#endif // REQUIRE_H ///:~