The boost::uuids::nil_generator class always generates a nil uuid. This file includes all the uuid generators for convenience. Std::size_t uuid_hash_value = uuid_hasher(boost::uuids::uuid()) This function allows uuids to be used with Three bits of a uuid determine the variant.īoost::uuids::uuid::variant_type v = u.variant() įour bits of a uuid determine the variant, that is the mechanismīoost::uuids::uuid::version_type v = u.version() īoth boost::uuids::uuid::swap() and boost::uuids::swap()Īll of the standard numeric operators are defined for the uuid : tag(boost::uuids::random_generator()())īool operator=(object const& rhs) const. see boost/libs/uuid/test/test_tagging.cpp example of tagging an object with a uuid Note that enabling more advanced extensions implies that more basic ones are also available. The library performs no run time checks, so if an extension is missing, the program will likely crash. Do not enable these extensions unless you're certain that they will always be available on any machine that will run your program. The BOOST_UUID_USE_SSE* macros can be defined by users, if auto-detection fails and it is known that the target CPU will have the extension. If defined, enables optimizations for SSE4.1 exstensions available in modern x86 processors.īy default the library attempts to detect the availability of SIMD extensions in the target CPU at compile time and automatically defines the appropriate macros if succeeded. If defined, enables optimizations for SSE3 exstensions available in modern x86 processors. If defined, enables optimizations for SSE2 exstensions available in modern x86 processors. By default, optimized algorithms are used, when the library is able to detect the availability of SIMD extensions at compile time. This may result in suboptimal performance. Generic versions of algorithms will be used instead. If defined, disables any optimizations for SIMD-enabled processors. These macros are summarized in the following table. However, there are a few options that can be enabled by defining macros prior to The library does not require building or any special configuration to be used. Never be generated again), or it is extremely likely to be unique (depending Generated UUIDs (that is, it has never been generated before and it will Optionally encode author cluster/region details in the low order bytes to resolve. Mechanisms, they are either guaranteed to be unique, different from all other The issue would be using a UUID generator (there are many versions. When UUIDs are generated by one of the defined Another is that the creation of UUIDsĭoes not require a centralized authority. UUIDs are also a basisįor OIDs (object identifiers), and URNs (uniform resource name).Īn attractive feature of UUIDs when compared to alternatives is their relative In this example, a randomly generated UUID is fetched using the randomuuid function. This function can be used to generate values for columns of type UUID in an INSERT or UPDATE SQL statements. Video streams in the Advanced Systems Format (ASF). The function randomuuid returns a randomly generated UUID, as a string of 36 characters. UUIDs are inserted intoĭocuments from Microsoft Office programs. Microsoft's component object model (COM) uses UUIDs toĭistinguish different software component interfaces. Transactions and classes involved in serialization may be Distributed computing may use UUIDs to identify a remote May be identified with a UUID to ensure that different parts of a message are putīack together again. To identify rows or records in order to ensure that they are unique acrossĭifferent databases, or for publication/subscription services. Some examples follow: Databases may use UUIDs To reliably identify very persistent objects across a network. It can be used to tag objects with very short lifetimes, or Information in a distributed environment without significant centralĬoordination. Uuid ContentsĪ UUID, or Universally unique identifier, is intended to uniquely identify Thisbyte = right( hex( dec, "integer" ), 2 ) ĭisclaimer: I believe I blindly followed this link and I didn't do extensive testing.This is the documentation for an old version of boost.Ĭlick here for the latest Boost documentation. Here is a method to create a UUID: newuuid = function(,ĭec = dec + (num(left(bin, 1))*2)^(num(length(bin))-1)
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