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class Reference
inherits Object

Reference is the base class of classes you define in your program. It is set as a class' superclass when you don't specify one:

class MyClass # < Reference
end

A reference type is passed by reference: when you pass it to methods, return it from methods or assign it to variables, a pointer is actually passed.

Invoking new on a Reference allocates a new instance on the heap. The instance's memory is automatically freed (garbage-collected) when the instance is no longer referred by any other entity in the program.

Direct known subclasses

Array(T) Benchmark::BM::Job Benchmark::BM::Tms Benchmark::IPS::Entry Benchmark::IPS::Job Box(T) Channel(T) Compress::Gzip::Header Compress::Zip::File Compress::Zip::File::Entry Compress::Zip::Reader Compress::Zip::Reader::Entry Compress::Zip::Writer Compress::Zip::Writer::Entry Crypto::Bcrypt Crypto::Bcrypt::Password Crypto::Blowfish Crystal::AbstractDefChecker Crystal::ASTNode Crystal::CacheDir Crystal::ClassVarInitializer Crystal::Codegen::Target Crystal::CodeGenVisitor::Context Crystal::CodeGenVisitor::LLVMVar Crystal::CodeGenVisitor::Phi Crystal::Command Crystal::Command::FormatCommand Crystal::Compiler Crystal::Compiler::CompilationUnit Crystal::ContextResult Crystal::CrystalLibraryPath Crystal::CrystalLLVMBuilder Crystal::Doc::Constant Crystal::Doc::Generator Crystal::Doc::Macro Crystal::Doc::Markdown::HTMLRenderer Crystal::Doc::Markdown::Parser Crystal::Doc::Method Crystal::Doc::ProjectInfo Crystal::Doc::RelativeLocation Crystal::Doc::Type Crystal::ExhaustivenessChecker::Target Crystal::Formatter::CommentInfo Crystal::HierarchyPrinter Crystal::ImplementationResult Crystal::ImplementationTrace Crystal::Init::Config Crystal::Init::InitProject Crystal::Init::View Crystal::InstanceVarInitializerContainer::InstanceVarInitializer Crystal::Lexer Crystal::LiteralExpander Crystal::LLVMId Crystal::LLVMTyper Crystal::Location Crystal::Macros::ASTNode Crystal::Match Crystal::MatchContext Crystal::NilReason Crystal::Playground::Agent Crystal::Playground::EnvironmentHandler Crystal::Playground::PageHandler Crystal::Playground::PlaygroundPage Crystal::Playground::Server Crystal::Playground::Session Crystal::Playground::WorkbookHandler Crystal::PrettyTypeNameJsonConverter Crystal::ProgressTracker Crystal::RecursiveStructChecker Crystal::TablePrint Crystal::TablePrint::Cell Crystal::TablePrint::Column Crystal::Token Crystal::Transformer Crystal::Type Crystal::TypeDeclarationProcessor::InitializeInfo Crystal::TypeDeclarationProcessor::InstanceVarTypeInfo Crystal::TypeFilter Crystal::TypeGuessVisitor::TypeInfo Crystal::VirtualFile Crystal::Visitor CSV CSV::Builder CSV::Lexer CSV::Parser Deque(T) Digest Dir Exception Fiber Hash(K, V) HTTP::Client HTTP::Client::Response HTTP::CompressHandler HTTP::Cookie HTTP::Cookies HTTP::ErrorHandler HTTP::FormData::Builder HTTP::FormData::Parser HTTP::LogHandler HTTP::Request HTTP::Server HTTP::Server::Context HTTP::Server::RequestProcessor HTTP::StaticFileHandler HTTP::WebSocket HTTP::WebSocketHandler IO Iterator::Stop JSON::Builder JSON::Lexer JSON::Parser JSON::PullParser JSON::Token Levenshtein::Finder LLVM::ABI LLVM::ABI::FunctionType LLVM::Builder LLVM::Context LLVM::FunctionPassManager LLVM::GenericValue LLVM::JITCompiler LLVM::MemoryBuffer LLVM::Module LLVM::ModulePassManager LLVM::PassManagerBuilder LLVM::TargetMachine Log Log::AsyncDispatcher Log::Backend Log::Builder Log::EntriesChecker Log::Metadata Log::SyncDispatcher MIME::Multipart::Builder MIME::Multipart::Parser Mutex OAuth2::AccessToken OAuth2::Client OAuth2::Session OAuth::AccessToken OAuth::Consumer OAuth::RequestToken OpenSSL::Cipher OpenSSL::HMAC OpenSSL::MD5 OpenSSL::SHA1 OpenSSL::SSL::Context OpenSSL::SSL::Server OptionParser PrettyPrint Process Process::Status Random::ISAAC Random::PCG32 Regex Spec::Context Spec::Example Steppable::StepIterator(T, L, B) String StringPool StringScanner System::Group System::User Time::Location URI URI::Params::Builder URI::Punycode WeakRef(T) XML::Attributes XML::Builder XML::Namespace XML::Node XML::NodeSet XML::Reader XML::XPathContext YAML::Builder YAML::Nodes::Builder YAML::Nodes::Node YAML::ParseContext YAML::PullParser

Class methods

.new

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Methods

#==(other : self)

Returns true if this reference is the same as other. Invokes same?.

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#==(other : JSON::Any)

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#==(other : YAML::Any)

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#==(other)

Returns false (other can only be a Value here).

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#dup

Returns a shallow copy of this object.

This allocates a new object and copies the contents of self into it.

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#hash(hasher)

See Object#hash(hasher)

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#inspect(io : IO) : Nil

Appends a String representation of this object which includes its class name, its object address and the values of all instance variables.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).inspect # => #<Person:0x10fd31f20 @name="John", @age=32>
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#object_id : UInt64

Returns a UInt64 that uniquely identifies this object.

The returned value is the memory address of this object.

string = "hello"
string.object_id # => 4460249568

pointer = Pointer(String).new(string.object_id)
string2 = pointer.as(String)
string2.object_id == string.object_id # => true
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#pretty_print(pp) : Nil

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#same?(other : Reference)

Returns true if this reference is the same as other. This is only true if this reference's object_id is the same as other's.

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#same?(other : Nil)

Returns false: a reference is never nil.

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#to_s(io : IO) : Nil

Appends a short String representation of this object which includes its class name and its object address.

class Person
  def initialize(@name : String, @age : Int32)
  end
end

Person.new("John", 32).to_s # => #<Person:0x10a199f20>
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