const_string1.hh
上传用户:dzyhzl
上传日期:2019-04-29
资源大小:56270k
文件大小:4k
- #ifndef __const_string1_hh__
- #define __const_string1_hh__
- #include <stdexcept>
- #include <string>
- #include <iostream>
- using namespace std ;
- //: A special string that is created from a existing const char *
- // It contains a small subset of the standard string class. When an
- // object is created only a link to the const char * is created. The
- // data is NOT copied. thus the const char * needs to stick around
- // for the life of the class.
- class const_string
- {
- private:
- const char *str_data;
- public:
- typedef const char value_type; //:
- typedef unsigned int size_type; //:
- typedef int difference_type; //:
- typedef const char& const_reference; //:
- typedef const_reference reference; //:
- typedef const char* const_pointer; //:
- typedef const_pointer pointer; //:
- typedef const char* const_iterator; //:
- typedef const_iterator iterator;
- //: The same as const_iterator because the data can not be changed.
-
- const_string() : str_data("") {} //:
- const_string(const char *str) : str_data(str) {} //:
- const_string& operator = (const char *str) //:
- {str_data = str; return *this;}
-
- size_type size() const //:
- { register int i = 0;
- while (str_data[i]) i++;
- return i;
- }
- const_iterator begin() const {return str_data;} //:
- const_iterator end() const {return str_data + size();} //:
- size_type length() const {return size();} //:
- size_type max_size() const {return size();} //:
-
- const_reference operator[](size_type pos) const {return str_data[pos];} //:
- const_reference at(size_type pos) const //:
- {
- if (pos >= size()) throw out_of_range("");
- else return str_data[pos];
- }
-
- const char* c_str() const {return str_data;} //:
- const char* data() const {return str_data;} //:
-
- int compare(const const_string& str) const //:
- {
- const char* str1 = str_data;
- const char* str2 = str.str_data;
- while (*str1 == *str2 && (*str1 || *str2)) {str1++; str2++;}
- return *str1-*str2;
- }
- };
- //------------------------------------------------------------------
- // ??? forgot inline directive. added to avoid linker errors
- inline ostream& operator << (ostream &o, const const_string &str)
- {
- return o << str.c_str();
- }
- //---------------------------------------------------------------------
- inline int compare (const const_string &lhs, const const_string &rhs)
- {
- return lhs.compare(rhs);
- }
- //--------------------------------------------------------------------
- inline bool operator == (const_string &lhs, const_string &rhs)
- {
- return compare(lhs,rhs) == 0;
- }
- //--------------------------------------------------------------------
- inline bool operator != (const_string &lhs, const_string &rhs)
- {
- return compare(lhs,rhs) != 0;
- }
- //--------------------------------------------------------------------
- inline bool operator < (const_string &lhs, const_string &rhs)
- {
- return compare(lhs,rhs) < 0;
- }
- //-------------------------------------------------------------------
- inline bool operator <= (const_string &lhs, const_string &rhs)
- {
- return compare(lhs,rhs) <= 0;
- }
- //-------------------------------------------------------------------
- inline bool operator > (const_string &lhs, const_string &rhs)
- {
- return compare(lhs,rhs) > 0;
- }
- //--------------------------------------------------------------------
- inline bool operator >= (const_string &lhs, const_string &rhs)
- {
- return compare(lhs,rhs) >= 0;
- }
- //--------------------------------------------------------------------
- #endif
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