C++程序开发实训
B方式【正常学习方式】：
一、设计mystring类，要求实现以下功能：
1、http://www.cplusplus.com/reference/cstring/ 中右边后涉及的所有功能。（共24个）
2、实现以下功能。（共9个）。功能描述与使用见：http://www.cplusplus.com/reference/string/
stoi Convert string to integer
stol Convert string to long int
stoul Convert string to unsigned integer
stoll Convert string to long long
stoull Convert string to unsigned long long
stof Convert string to float
stod Convert string to double
stold Convert string to long double
to_string Convert numerical value to string
3、Construct string object。（共6个）。功能描述与使用见：http://www.cplusplus.com/reference/string/string/string/
Constructs a string object, initializing its value depending on the constructor version used:
(1) empty string constructor (default constructor)
Constructs an empty string, with a length of zero characters.
(2) copy constructor
Constructs a copy of str.
(3) substring constructor
Copies the portion of str that begins at the character position pos and spans len characters (or until the end of str, if either str is too short or if len is string::npos).
(4) from c-string
Copies the null-terminated character sequence (C-string) pointed by s.
(5) from buffer
Copies the first n characters from the array of characters pointed by s.
(6) fill constructor
Fills the string with n consecutive copies of character c.
4、实现以下功能。（共40个）功能描述与使用见：http://www.cplusplus.com/reference/string/string/
(destructor) String destructor
operator= String assignment
size Return length of string
length Return length of string
Capacity:
size
Return length of string (public member function )
length
Return length of string (public member function )
max_size
Return maximum size of string (public member function )
resize
Resize string (public member function )
capacity
Return size of allocated storage (public member function )
reserve
Request a change in capacity (public member function )
clear
Clear string (public member function )
empty
Test if string is empty (public member function )
shrink_to_fit
Shrink to fit (public member function )
Element access:
operator[]
Get character of string (public member function )
at
Get character in string (public member function )
back
Access last character (public member function )
front
Access first character (public member function )
Modifiers:
operator+=
Append to string (public member function )
append
Append to string (public member function )
push_back
Append character to string (public member function )
assign
Assign content to string (public member function )
insert
Insert into string (public member function )
erase
Erase characters from string (public member function )
replace
Replace portion of string (public member function )
swap
Swap string values (public member function )
pop_back
Delete last character (public member function )
String operations:
data
Get string data (public member function )
copy
Copy sequence of characters from string (public member function )
find
Find content in string (public member function )
rfind
Find last occurrence of content in string (public member function )
find_first_of
Find character in string (public member function )
find_last_of
Find character in string from the end (public member function )
find_first_not_of
Find absence of character in string (public member function )
find_last_not_of
Find non-matching character in string from the end (public member function )
substr
Generate substring (public member function )
compare
Compare strings (public member function )
Non-member function overloads
operator+
Concatenate strings (function )
relational operators
Relational operators for string (function )
swap
Exchanges the values of two strings (function )
operator>>
Extract string from stream (function )
operator<<
Insert string into stream (function )
getline
Get line from stream into string (function )
5、测试
测试以上功能是否正确实现
二（选做，仅供有兴趣的同学练习，不参与评分）、封装mystring类，供Python调用。
三、评分标准：
功能实现占60%，程序可读性占40%。 做方式B的同学学生成绩不在微信群里公示，老师根据同学们的功能实现和程序可读性直接给出成绩。
友情提示：不懂的地方可以请教同学，但必须自己独立完成。自己做好的C++实践作业，做好保密工作，自己在教学在线上面提交，不要让别的同学COPY过去了。
DDL为2022年6月24日晚9点。
在此之后提交的同学，总评成绩乘以0.9的系数。
如果存在完全相同的两份作业，这两位同学均需要参加答辩，以确实哪一份是原创，哪一份是COPY件。COPY件的同学成绩计0分。