D programming Language
Download 1.66 Mb.
|
- Navigate this page:
- Properties for Integral Data Types
- .init Property
- Attributes
- Linkage Attribute
- Align Attribute
- Deprecated Attribute
- Protection Attribute
PropertiesEvery type and expression has properties that can be queried: int.size // yields float.nan // yields the floating point value (float).nan // yields the floating point nan value (3).size // yields 4 (because 3 is an int) 2.size // syntax error, since "2." is a floating point number int.init // default initializer for int's
.size size in bytes .max maximum value .min minimum value .sign should we do this?
Properties for Floating Point Types.init initializer (NaN) .size size in bytes .infinity infinity value .nan NaN value .sign 1 if -, 0 if + .isnan 1 if nan, 0 if not .isinfinite 1 if +-infinity, 0 if not .isnormal 1 if not nan or infinity, 0 if .digits number of digits of precision .epsilon smallest increment .mantissa number of bits in mantissa .maxExp maximum exponent as power of 2 (?) .max largest representable value that's not infinity .min smallest representable value that's not 0 .init Property.init produces a constant expression that is the default initializer. If applied to a type, it is the default initializer for that type. If applied to a variable or field, it is the default initializer for that variable or field. For example: int a; int b = 1; typedef int t = 2; t c;
t d = cast(t)3; int.init // is 0 a.init // is 0 b.init // is 1 t.init // is 2 c.init // is 2 d.init // is 3 struct Foo { int a; int b = 7; } Foo.a.init // is 0 Foo.b.init // is 7 AttributesAttributeSpecifier: Attribute : Attribute DeclDefBlock AttributeElseSpecifier: AttributeElse : AttributeElse DeclDefBlock AttributeElse DeclDefBlock else DeclDefBlock Attribute: LinkageAttribute AlignAttribute deprecated private protected public export static final override abstract const auto AttributeElse: DebugAttribute VersionAttribute DeclDefBlock DeclDef { } { DeclDefs } Attributes are a way to modify one or more declarations. The general forms are: attribute declaration; affects the declaration
declaration; declaration; ...
{ declaration; declaration; ...
} For attributes with an optional else clause: attribute declaration; else declaration; attribute affects all declarations in the block { declaration; declaration; ...
} else
{ declaration; declaration; ...
} Linkage AttributeLinkageAttribute: extern extern ( LinkageType )
D provides an easy way to call C functions and operating system API functions, as compatibility with both is essential. The LinkageType is case sensitive, and is meant to be extensible by the implementation (they are not keywords). C and D must be supplied, the others are what makes sense for the implementation. Implementation Note: for Win32 platforms, Windows and Pascal should exist. C function calling conventions are specified by: extern (C): int foo(); call foo() with C conventions D conventions are: extern (D): or:
extern: Windows API conventions are: extern (Windows): void *VirtualAlloc( void *lpAddress, uint dwSize, uint flAllocationType, uint flProtect );
align align ( Integer ) Specifies the alignment of struct members. align by itself sets it to the default, which matches the default member alignment of the companion C compiler. Integer specifies the alignment which matches the behavior of the companion C compiler when non-default alignments are used. A value of 1 means that no alignment is done; members are packed together. Deprecated AttributeIt is often necessary to deprecate a feature in a library, yet retain it for backwards compatiblity. Such declarations can be marked as deprecated, which means that the compiler can be set to produce an error if any code refers to deprecated declarations: deprecated { void oldFoo(); } Implementation Note: The compiler should have a switch specifying if deprecated declarations should be compiled with out complaint or not. Protection AttributeProtection is an attribute that is one of private, protected, public or export. Private means that only members of the enclosing class can access the member, or members and functions in the same module as the enclosing class. Private members cannot be overridden. Private module members are equivalent to static declarations in C programs. Protected means that only members of the enclosing class or any classes derived from that class can access the member. Protected module members are illegal. Public means that any code within the executable can access the member. Export means that any code outside the executable can access the member. Export is analogous to exporting definitions from a DLL.
Directory: upload upload -> 587 Return function, r i(X) r i(0) r i(1) r i(2) r i(3) 1 0 2 4 6 Thermal Station, I 2 0 1 5 6 3 0 3 5 6 10 upload -> Department of science and humanities department of mathematics part-a questions and answers upload -> The Case Against the nypd’s Quota-Driven ‘Broken Windows’ Policing What Is It? upload -> For want of a nail upload -> Traditional British values upload -> Tv shows, Made for tv movies, Mini Series & Internet Programs Shot at Paramount Ranch upload -> Ownership Models There are two different types of ownership models upload -> Police Militarization upload -> City of rising star regular meting thursday, july 14, 2016 upload -> Township of winfield Download 1.66 Mb. Share with your friends:
|