9.0 KiB
| title |
|---|
| basic_string_view |
{{< callout type="info">}}
Header: string_view.h
Similar to:
std::basic_string_view
std::string_view
std::wstring_view
std::u8string_view
std::u16string_view
std::u32string_view
{{< /callout >}}
This class implements a view in to a range of a C string, etl::string (+ variants), std::string (+ variants).
Classes
etl::basic_string_view<typename T, typename TTraits = etl::char_traits<T>>
Types
etl::string_view
etl::wstring_view
etl::u8string_view;
etl::u16string_view
etl::u32string_view
Member types
value_type T
size_type std::size_t
difference_type std::ptrdiff_t
reference value_type&
const_reference const value_type&
pointer value_type*
const_pointer const value_type*
iterator Random access iterator
const_iterator Constant random access iterator
reverse_iterator std::reverse_iterator<iterator>
const_reverse_iterator std::reverse_iterator<const_iterator>
Constants
size_t npos
Description
An end of view indicator by the functions that expect a view index.
An error indicator for functions that return a view index.
Constructors
ETL_CONSTEXPR basic_string_view()
Description
Default constructor.
ETL_CONSTEXPR basic_string_view(const T* begin, size_t size)
Description
Construct from a start and size.
ETL_CONSTEXPR basic_string_view(const T* begin)
Description
Construct from a zero terminated string.
ETL_CONSTEXPR basic_string_view(const etl::basic_string_view& other)
Description
Copy constructor.
Modifiers
void remove_prefix(size_t n)
Description
Shrinks the view from the front.
Undefined behaviour if n is larger than the string.
void remove_suffix(size_t n)
Description
Shrinks the view from the back.
Undefined behaviour if n is larger than the string.
void swap(etl::basic_string_view<T, TTraits>& view)
Description
Swaps with another view.
Element access
const T& at(size_t i) const
Description
Returns a const reference to the indexed element.
Emits an etl::string_view_uninitialised if the view is not initialised.
Emits an etl::string_view_bounds if the index is not in range.
If asserts or exceptions are not enabled then undefined behaviour occurs.
const_reference operator[](size_t i) const
Description
Returns a const reference to the indexed element.
Undefined behaviour if the string is empty.
const_reference front() const
Description
Returns a const reference to the first element.
Undefined behaviour if the string is empty.
const_reference back() const
Description
Returns a const reference to the last element.
Undefined behaviour if the string is empty.
const_pointer data() const
Description
Returns a const pointer to the first element.
Undefined behaviour if the string is empty.
Iterators
const_iterator begin() const
const_iterator cbegin() const
Description
Returns an iterator to the beginning of the string view.
const_iterator end() const
const_iterator cend() const
Description
Returns an iterator to the end of the string view.
const_iterator rbegin() const
const_iterator crbegin() const
Description
Returns a reverse iterator to the beginning of the string view.
const_iterator rend() const
const_iterator crend() const
Description
Returns a reverse iterator to the end of the string view.
Operations
size_t copy(T* destination, size_t count, size_t position = 0) const
Description
Copies the sub-string at position for count characters or size() - count, whichever smaller, to the string pointed to by destination.
basic_string_view substr(size_t position = 0, size_t count = npos) const
Description
Returns a view which is the sub-string at position for count characters or size() - count, whichever smaller.
Capacity
bool empty() const
Description
Returns true if the size of the string view is zero, otherwise false.
size_t size() const
Description
Returns the size of the view.
size_t length() const
Description
Alternative for size().
size_t max_size() const
Description
Returns the maximum possible size of the view.
Compare
int compare(basic_string_view v) const
int compare(size_t position1, size_t count1, basic_string_view view) const
int compare(size_t position1, size_t count1,
basic_string_view view,
size_t position2, size_t count2) const
int compare(const T* text) const
int compare(size_t position1, size_t count, const T* text) const
int compare(size_t position1, size_t count1, const T* text, size_t count2) const
Description
Compares two character sequences.
Search
bool starts_with(etl::basic_string_view view) const
bool starts_with(T x) const
bool starts_with(const T* x) const
Description
Checks if the string view begins with the given prefix.
bool ends_with(etl::basic_string_view view) const
bool ends_with(T x) const
bool ends_with(const T* x) const
Description
Checks if the string view ends with the given prefix.
size_t find(basic_string_view view, size_type position = 0) const
size_t find(T c, size_t position = 0) const
size_t find(const T* text, size_t position, size_t count) const
size_t find(const T* text, size_t position = 0) const;
Description
Finds the first sub-string equal to the given character sequence.
size_t rfind(basic_string_view view, size_t position = npos) const
size_t rfind(T c, size_t position = npos) const
size_t rfind(const T* text, size_t position, size_t count) const
size_t rfind(const T* text, size_t position = npos) const
Description
Finds the last sub-string equal to the given character sequence.
size_t find_first_of(basic_string_view view, size_t position = 0) const
size_t find_first_of(T c, size_t position = 0) const
size_t find_first_of(const T* text, size_t position, size_t count) const
size_t find_first_of(const T* text, size_t position = 0) const
Description
Finds the first character equal to any of the characters in the given character sequence.
size_t find_last_of(basic_string_view view, size_t position = npos) const
size_t find_last_of(T c, size_t position = npos) const
size_t find_last_of(const T* text, size_t position, size_type count) const
size_t find_last_of(const T* text, size_t position = npos) const
Description
Finds the last character equal to any of the characters in the given character sequence.
size_t find_first_not_of(basic_string_view view, size_t position = 0) const
size_t find_first_not_of(T c, size_t position = 0) const
size_t find_first_not_of(const T* text, size_t position, size_t count) const
size_t find_first_not_of(const T* text, size_t position = 0) const
Description
Finds the first character not equal to any of the characters in the given character sequence.
size_t find_last_not_of(basic_string_view view, size_t position = npos) const
size_t find_last_not_of(T c, size_t position = npos) const
size_t find_last_not_of(const T* text, size_t position, size_t count) const
size_t find_last_not_of(const T* text, size_t position = npos) const
Description
Finds the first character not equal to any of the characters in the given character sequence.
Non-member functions
Lexicographically comparisons
== true if the contents of the string views are equal,
otherwise false.
!= true if the contents of the string views are not equal,
otherwise false.
< true if the contents of the lhs are lexicographically less than the contents of the rhs,
otherwise false.
<= true if the contents of the lhs are lexicographically less than or equal to the contents of the rhs,
otherwise false.
> true if the contents of the lhs are lexicographically greater than the contents of the rhs,
otherwise false.
>= true if the contents of the lhs are lexicographically greater than or equal to the contents of the rhs,
otherwise false.
void swap(etl::basic_string_view<T, TTraits> lhs,
etl::basic_string_view<T, TTraits> rhs)
Swaps two views.
Hash
etl::hash<etl::string_view>
etl::hash<etl::wstring_view>
etl::hash<etl::u8string_view>
etl::hash<etl::u16string_view>
etl::hash<etl::u32string_view>
---
**Example**
```cpp
etl::string<10> greeting("Hello World");
using View = etl::string_view;
View view(greeting.begin() + 2, greeting.size() - 4);
void Print(const View& view)
{
std::cout << std::string(view.begin(), view.end());
}
Print(view); // Prints "llo Wo"
size_t hashvalue = etl::hash<View>()(view);