std::ctype<CharT>::toupper, std::ctype<CharT>::do_toupper

来自cppreference.com
< cpp‎ | locale‎ | ctype
 
 
 
 
定义于头文件 <locale>
public:
CharT toupper( CharT c ) const;
(1)
public:
const CharT* toupper( CharT* beg, const CharT* end ) const;
(2)
protected:
virtual CharT do_toupper( CharT c ) const;
(3)
protected:
virtual const CharT* do_toupper( CharT* beg, const CharT* end ) const;
(4)
1,2) 公开成员函数,调用最终导出类上的受保护虚成员函数 do_toupper
3) 若此 locale 定义 c 的大写形式,则转换它为大写形式。
4) 对字符数组 [beg, end) 中每个存在大写形式的字符,以其大写形式替换该字符。

参数

c - 要转换的字符
beg - 指向要转换的数组中首字符的指针
end - 指向要转换的数组尾后一位置的指针

返回值

1,3) 大写字符,或若无列于此 loacale 的大写形式则为 c
2,4) end

注意

此函数只能进行 1:1 字符映射,例如 'ß' 的大写形式(有一些例外)是双字符字符串 "SS" ,它无法以 do_toupper 获得。

示例

#include <locale>
#include <iostream>
 
void try_upper(const std::ctype<wchar_t>& f, wchar_t c)
{
    wchar_t up = f.toupper(c);
    if (up != c) {
        std::wcout << "Upper case form of \'" << c << "' is " << up << '\n';
    } else {
        std::wcout << '\'' << c << "' has no upper case form\n";
    }
}
 
int main()
{
    std::locale::global(std::locale("en_US.utf8"));
    std::wcout.imbue(std::locale());
    std::wcout << "In US English UTF-8 locale:\n";
    auto& f = std::use_facet<std::ctype<wchar_t>>(std::locale());
    try_upper(f, L's');
    try_upper(f, L'ſ');
    try_upper(f, L'ß');
 
    std::wstring str = L"Hello, World!";
    std::wcout << "Uppercase form of the string '" << str << "' is ";
    f.toupper(&str[0], &str[0] + str.size());
    std::wcout << "'" << str << "'\n";
}

输出:

In US English UTF-8 locale:
Upper case form of 's' is S
Upper case form of 'ſ' is S
'ß' has no upper case form
Uppercase form of the string 'Hello, World!' is 'HELLO, WORLD!'

参阅

调用 do_tolower
(公开成员函数)
转换字符为大写
(函数)
转换宽字符为大写
(函数)