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Defined in header <string> | ||
unsignedlong stoul(conststd::string& str, std::size_t* pos= nullptr,int base=10); | (1) | (since C++11) |
unsignedlong stoul(conststd::wstring& str, std::size_t* pos= nullptr,int base=10); | (2) | (since C++11) |
unsignedlonglong stoull(conststd::string& str, std::size_t* pos= nullptr,int base=10); | (3) | (since C++11) |
unsignedlonglong stoull(conststd::wstring& str, std::size_t* pos= nullptr,int base=10); | (4) | (since C++11) |
Interprets an unsigned integer value in the stringstr.
Letptr be an internal (to the conversion functions) pointer of typechar*(1,3) orwchar_t*(2,4), accordingly.
Discards any whitespace characters (as identified by callingstd::isspace) until the first non-whitespace character is found, then takes as many characters as possible to form a validbase-n (where n=base) unsigned integer number representation and converts them to an integer value. The valid unsigned integer value consists of the following parts:
0) indicating octal base (applies only when the base is8 or0)0x or0X) indicating hexadecimal base (applies only when the base is16 or0)The set of valid values for base is{0, 2, 3, ..., 36}. The set of valid digits for base-2 integers is{0, 1}, for base-3 integers is{0, 1, 2}, and so on. For bases larger than10, valid digits include alphabetic characters, starting fromAa for base-11 integer, toZz for base-36 integer. The case of the characters is ignored.
Additional numeric formats may be accepted by the currently installed Clocale.
If the value ofbase is0, the numeric base is auto-detected: if the prefix is0, the base is octal, if the prefix is0x or0X, the base is hexadecimal, otherwise the base is decimal.
If the minus sign was part of the input sequence, the numeric value calculated from the sequence of digits is negated as if byunary minus in the result type, which applies unsigned integer wraparound rules.
Ifpos is not a null pointer, thenptr will receive the address of the first unconverted character instr.c_str(), and the index of that character will be calculated and stored in*pos, giving the number of characters that were processed by the conversion.
Contents |
| str | - | the string to convert |
| pos | - | address of an integer to store the number of characters processed |
| base | - | the number base |
The string converted to the specified unsigned integer type.
| This section is incomplete Reason: no example |
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
| DR | Applied to | Behavior as published | Correct behavior |
|---|---|---|---|
| LWG 2009 | C++11 | std::out_of_range would not be thrown if std::strtoul orstd::strtoull setserrno toERANGE | will throw |
(C++11)(C++11)(C++11) | converts a string to a signed integer (function)[edit] |
(C++11)(C++11)(C++11) | converts a string to a floating point value (function)[edit] |
