Difference between revisions of "cpp/string/byte/strtoul"
m (Text replace - "{{mark c++0x feature}}" to "{{mark c++11 feature}}") |
m (Text replace - "character string" to "byte string") |
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− | Interprets an unsigned integer value in a | + | Interprets an unsigned integer value in a byte string pointed to by {{tt|str}}. |
{{cpp/string/cvt str2int base | base=base | u=true}} | {{cpp/string/cvt str2int base | base=base | u=true}} | ||
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===Parameters=== | ===Parameters=== | ||
{{param list begin}} | {{param list begin}} | ||
− | {{param list item | str | pointer to the null-terminated | + | {{param list item | str | pointer to the null-terminated byte string to be interpreted}} |
{{param list item | str_end | pointer to a pointer to character.}} | {{param list item | str_end | pointer to a pointer to character.}} | ||
{{param list item | base | ''base'' of the interpreted integer value}} | {{param list item | base | ''base'' of the interpreted integer value}} |
Revision as of 02:22, 26 November 2011
Template:cpp/string/narrow/sidebar Template:ddcl list begin <tr class="t-dsc-header">
<td><cstdlib>
<td></td> <td></td> </tr> <tr class="t-dcl ">
<td class="t-dcl-nopad"><td class="t-dcl-nopad"> </td> <td class="t-dcl-nopad"> </td> </tr> <tr class="t-dcl ">
<td ><td class="t-dcl-nopad"> </td> <td > Template:mark c++11 feature </td> </tr> Template:ddcl list end
Interprets an unsigned integer value in a byte string pointed to by str
.
Discards any whitespace characters (as identified by calling std::isspace) until the first non-whitespace character is found, then takes as many characters as possible to form a valid base-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:
- (optional) plus or minus sign
- (optional) prefix (
0
) indicating octal base (applies only when the base is 8 or 0) - (optional) prefix (
0x
or0X
) indicating hexadecimal base (applies only when the base is 16 or 0) - a sequence of digits
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 than 10
, valid digits include alphabetic characters, starting from Aa
for base-11
integer, to Zz
for base-36
integer. The case of the characters is ignored.
Additional numeric formats may be accepted by the currently installed C locale.
If the value of base
is 0, the numeric base is auto-detected: if the prefix is 0
, the base is octal, if the prefix is 0x
or 0X
, 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 by unary minus in the result type, which applies unsigned integer wraparound rules.
The functions sets the pointer pointed to by str_end
to point to the character past the last character interpreted. If str_end
is Template:cpp, it is ignored.
Contents |
Parameters
str | - | pointer to the null-terminated byte string to be interpreted |
str_end | - | pointer to a pointer to character. |
base | - | base of the interpreted integer value |
Return value
integer value corresponding to the contents of str
on success. If the converted value falls out of range of corresponding return type, range error occurs and ULONG_MAX
or ULLONG_MAX
is returned. If no conversion can be performed, Template:cpp is returned.
This section is incomplete Reason: fix links to limits |