folly::Range

Synopsis

Declared in <folly/Range.h>

template<class Iter>
class Range;

Description

A Range refers to the half-open interval [begin, end)] delimited by a pair of iterators. It does not own or manage the underlying data, so the referenced storage must outlive the range.

Type Aliases

Name	Description
`const_iterator`	The constant iterator type over the range.
`const_range_type`	The corresponding range type with a constant element type.
`const_reference`	The constant reference type to an element of the range.
`difference_type`	The signed integer type used for iterator differences.
`iterator`	The iterator type over the range.
`reference`	The reference type to an element of the range.
`size_type`	The unsigned integer type used for sizes and offsets.
`traits_type`	The character-traits-like type used for element comparisons.
`value_type`	The type of the elements referenced by the range.

Member Functions

Name	Description
`Range` [constructor]	Constructors
`operator=`	Assignment operators
`advance`	Advance the beginning of the range by a number of elements.
`assign`	Assign start and end iterators
`at`	Access the element at a given index with bounds checking.
`back`	Access the last element.
`begin`	Get the iterator to the first element.
`castToConst`	Get a copy of this range with a constant element type.
`cbegin`	Get the constant iterator to the first element.
`cend`	Get the constant iterator past the last element.
`clear`	Clear start and end iterators
`compare`	Lexicographically compare this range with another.
`contains`	`contains` overloads
`data`	Get a pointer or iterator to the first element.
`empty`	Check whether the range is empty.
`end`	Get the iterator past the last element.
`endsWith`	`endsWith` overloads
`ends_with`	`ends_with` overloads
`equals`	Compare this range with another for equality, using a custom comparator.
`erase`	Remove the items in [b, e), as long as this subrange is at the beginning] or end of the Range.
`find`	`find` overloads
`find_first_of`	`find_first_of` overloads
`front`	Access the first element.
`operator[]`	Access the element at a given index without bounds checking.
`pop_back`	Remove the last element from the range.
`pop_front`	Remove the first element from the range.
`removePrefix`	`removePrefix` overloads
`removeSuffix`	`removeSuffix` overloads
`replaceAll`	Replaces all occurrences of 'source' with 'dest'. Returns number of replacements made. Source and dest have to have the same length. Throws if the lengths are different. If 'source' is a pattern that is overlapping with itself, we perform sequential replacement: "aaaaaaa".replaceAll("aa", "ba") --> "bababaa"
`replaceAt`	Replaces the content of the range, starting at position 'pos', with contents of 'replacement'. Entire 'replacement' must fit into the range. Returns false if 'replacements' does not fit. Example use:
`reset`	`reset` overloads
`rfind`	Find the last occurrence of an element.
`size`	Get the number of elements in the range.
`split_step`	`split_step` overloads
`start`	Get the iterator to the first element.
`startsWith`	`startsWith` overloads
`starts_with`	`starts_with` overloads
`str`	Convert the range to a std::string. Works only for Range<const char> and Range<char>.
`subpiece`	Return a window into the current range, starting at first, and spanning length characters (or until the end of the current range, whichever comes first).
`substr`	Return a substring window into the range. Works only for character ranges.
`subtract`	Retract the end of the range by a number of elements.
`swap`	Swap the contents of this range with another.
`to`	`to` overloads
`toString`	Convert the range to a std::string.
`uncheckedAdvance`	Advance the beginning of the range without bounds checking.
`uncheckedSubpiece`	Return a subrange window without bounds checking.
`uncheckedSubtract`	Retract the end of the range without bounds checking.
`walk_size`	Get the number of elements by walking the iterators.
`operator Tgt`	Conversion operators

Static Data Members

Name	Description
`npos`	Sentinel offset returned by search functions when no match is found.

Non-Member Functions

Name	Description
`crange`	Create a constant range referencing a constant C array.
`crange`	Create a constant range referencing an initializer list.
`crange`	Create a constant range referencing the contents of a container.
`crange`	Create a constant range referencing a constant std::array.
`decodeVarint`	Decode a value from a given buffer, advances data past the returned value. Throws on error.
`operator!=`	Compare two ranges for inequality.
`operator!=`	Inequality operator
`operator""_sp`	Create a range from a `char32_t` string literal.
`operator""_sp`	Create a StringPiece from a `char` string literal.
`operator""_sp`	Create a range from a `char16_t` string literal.
`operator""_sp`	Create a range from a `char8_t` string literal.
`operator""_sp`	Create a range from a `wchar_t` string literal.
`operator<`	Test whether one range is lexicographically less than another.
`operator<=`	Test whether one range is lexicographically less than or equal to another.
`operator<=>`	Three-way comparison operator
`operator==`	Templated comparison operators
`operator==`	Equality operator
`operator>`	Test whether one range is lexicographically greater than another.
`operator>=`	Test whether one range is lexicographically greater than or equal to another.
`qfind`	Finds the first occurrence of needle in haystack. The result is the offset reported to the beginning of haystack, or string::npos if needle wasn't found.
`qfind`	Finds the first occurrence of needle in haystack. The algorithm is on average faster than O(haystack.size() * needle.size()) but not as fast as Boyer-Moore. On the upside, it does not do any upfront preprocessing and does not allocate memory.
`qfind_first_of`	Finds the first occurrence of any element of needle in haystack. The algorithm is O(haystack.size() * needle.size()).
`qfind_first_of`	Find the first occurrence of any element of needles in haystack, using a custom comparator.
`range`	Create a range referencing a C array.
`range`	Create a range referencing a constant std::array.
`range`	Create a range referencing the contents of a contiguous-storage container.
`range`	Create a range referencing an initializer list.
`range`	Create a range from two iterators, with type deduction.
`range`	Create a range referencing the contents of a constant container.
`range`	Create a range referencing a std::array.
`range`	Create a range referencing a constant C array.
`rfind`	Finds the last occurrence of needle in haystack. The result is the offset reported to the beginning of haystack, or string::npos if needle wasn't found.
`swap`	Swap the contents of two ranges.
`tag_invoke`	Returns a range that enumerates the set in order-preserving reinsertion order.
`tag_invoke`	Returns a range that enumerates the set in order-preserving reinsertion order.
`tag_invoke`	Returns a range that enumerates the map in order-preserving reinsertion order.
`tryDecodeVarint`	A variant of decodeVarint() that does not throw on error. Useful in contexts where only part of a serialized varint may be attempted to be decoded, e.g., when a serialized varint arrives on the boundary of a network packet.