sstring.h

来自「Thinking in C++ 2nd edition source code 」· C头文件 代码 · 共 71 行

//: C16:Sstring.h
// From Thinking in C++, 2nd Edition
// at http://www.BruceEckel.com
// (c) Bruce Eckel 1999
// Copyright notice in Copyright.txt
// Stack-based string
#ifndef SSTRING_H_
#define SSTRING_H_
#include <cstring>
#include <iostream>

template<int bsz = 0>
class SString {
  char buf[bsz + 1];
  char* s;
public:
  SString(const char* S = "") : s(buf) {
    if(!bsz) { // Make on heap
      s = new char[strlen(S) + 1];
      std::strcpy(s, S);
    } else { // Make on stack
      buf[bsz] = 0; // Ensure 0 termination
      std::strncpy(s, S, bsz);
    }
  }
  SString(const SString& rv) : s(buf) {
    if(!bsz) { // Make on heap
      s = new char[strlen(rv.s) + 1];
      std::strcpy(s, rv.s);
    } else { // Make on stack
      buf[bsz] = 0;
      std::strncpy(s, rv.s, bsz);
    }
  }
  SString& operator=(const SString& rv) {
    // Check for self-assignment:
    if(&rv == this) return *this;
    if(!bsz) { // Manage heap:
      delete s;
      s = new char[strlen(rv.s) + 1];
    }
    // Constructor guarantees length < bsz:
    std::strcpy(s, rv.s);
    return *this;
  }
  ~SString() {
    if(!bsz) delete []s;
  }
  int operator==(const SString& rv) const {
    return ! stricmp(s, rv.s);  // nonstandard
  }
  int operator!=(const SString& rv) const {
    return stricmp(s, rv.s);
  }
  int operator>(const SString& rv) const {
    return stricmp(s, rv.s) > 0;
  }
  int operator<(const SString& rv) const {
    return stricmp(s, rv.s) < 0;
  }
  char* str() const { return s; }
  friend std::ostream&
    operator<<(std::ostream& os,
               const SString<bsz>& S) {
      return os << S.s;
  }
};

typedef SString<> Hstring; // Heap string
#endif // SSTRING_H_ ///:~