21 Strings library [strings]

21.4 String view classes [string.view]

21.4.3 Class template basic_­string_­view [string.view.template]

21.4.3.8 Searching [string.view.find]

1
#
Member functions in this subclause have complexity at worst, although implementations should do better.
2
#
Let F be one of find, rfind, find_­first_­of, find_­last_­of, find_­first_­not_­of, and find_­last_­not_­of.
  • (2.1)
    Each member function of the form constexpr return-type F(const charT* s, size_type pos) const; has effects equivalent to: return F(basic_­string_­view(s), pos);
  • (2.2)
    Each member function of the form constexpr return-type F(const charT* s, size_type pos, size_type n) const; has effects equivalent to: return F(basic_­string_­view(s, n), pos);
  • (2.3)
    Each member function of the form constexpr return-type F(charT c, size_type pos) const noexcept; has effects equivalent to: return F(basic_­string_­view(addressof(c), 1), pos);
🔗
constexpr size_type find(basic_string_view str, size_type pos = 0) const noexcept;
3
#
Let xpos be the lowest position, if possible, such that the following conditions hold:
  • (3.1)
    pos <= xpos
  • (3.2)
    xpos + str.size() <= size()
  • (3.3)
    traits​::​eq(at(xpos + I), str.at(I)) for all elements I of the string referenced by str.
4
#
Effects: Determines xpos.
5
#
Returns: xpos if the function can determine such a value for xpos.
Otherwise, returns npos.
🔗
constexpr size_type rfind(basic_string_view str, size_type pos = npos) const noexcept;
6
#
Let xpos be the highest position, if possible, such that the following conditions hold:
  • (6.1)
    xpos <= pos
  • (6.2)
    xpos + str.size() <= size()
  • (6.3)
    traits​::​eq(at(xpos + I), str.at(I)) for all elements I of the string referenced by str.
7
#
Effects: Determines xpos.
8
#
Returns: xpos if the function can determine such a value for xpos.
Otherwise, returns npos.
🔗
constexpr size_type find_first_of(basic_string_view str, size_type pos = 0) const noexcept;
9
#
Let xpos be the lowest position, if possible, such that the following conditions hold:
  • (9.1)
    pos <= xpos
  • (9.2)
    xpos < size()
  • (9.3)
    traits​::​eq(at(xpos), str.at(I)) for some element I of the string referenced by str.
10
#
Effects: Determines xpos.
11
#
Returns: xpos if the function can determine such a value for xpos.
Otherwise, returns npos.
🔗
constexpr size_type find_last_of(basic_string_view str, size_type pos = npos) const noexcept;
12
#
Let xpos be the highest position, if possible, such that the following conditions hold:
  • (12.1)
    xpos <= pos
  • (12.2)
    xpos < size()
  • (12.3)
    traits​::​eq(at(xpos), str.at(I)) for some element I of the string referenced by str.
13
#
Effects: Determines xpos.
14
#
Returns: xpos if the function can determine such a value for xpos.
Otherwise, returns npos.
🔗
constexpr size_type find_first_not_of(basic_string_view str, size_type pos = 0) const noexcept;
15
#
Let xpos be the lowest position, if possible, such that the following conditions hold:
  • (15.1)
    pos <= xpos
  • (15.2)
    xpos < size()
  • (15.3)
    traits​::​eq(at(xpos), str.at(I)) for no element I of the string referenced by str.
16
#
Effects: Determines xpos.
17
#
Returns: xpos if the function can determine such a value for xpos.
Otherwise, returns npos.
🔗
constexpr size_type find_last_not_of(basic_string_view str, size_type pos = npos) const noexcept;
18
#
Let xpos be the highest position, if possible, such that the following conditions hold:
  • (18.1)
    xpos <= pos
  • (18.2)
    xpos < size()
  • (18.3)
    traits​::​eq(at(xpos), str.at(I)) for no element I of the string referenced by str.
19
#
Effects: Determines xpos.
20
#
Returns: xpos if the function can determine such a value for xpos.
Otherwise, returns npos.