được gọi là một deallocator lớp. Deallocator phải có chính xác một tham số của kiểu void *. Chỉ có một có thể được chỉ định cho một lớp. Khi một biểu hiện xóa:Một lớp tự động là một lớp học với các thuộc tính tự động, như trong:char [] tham gia (char [] p1, char [] p2) Tham gia hai thành phần con | The D Programming Language int k error k already defined i 3 x i uses the i declared above There is no else clause for a debug statement as debug statements should add code not subtract code. Version Statement It is commonplace to conveniently support multiple versions of a module with a single source file. While the D way is to isolate all versioning into separate modules that can get burdensome if it s just simple line change or if the entire program would otherwise fit into one module. Versionstatement Versionpredicate statement Versionpredicate statement else statement Versionpredicate version Integer version Identifier The version statement conditionally compiles in its statement body based on the version specified by the Integer of Identifier. Both forms are set by the -version switch to the compiler. If Statement is a block statement it does not introduce a new scope. For example int k version Demo compile in this code block for the demo version int i int k error k already defined i 3 x i uses the i declared above The version statement works together with the version attribute for declarations. Version statements can nest. The optional else clause gets conditionally compiled in if the version predicate is false version X86 . implement custom inline assembler version else . use default but slow version While the debug and version statements superficially behave the same they are intended for very different purposes. Debug statements are for adding debug code that is removed for the release version. Version statements are to aid in portability and multiple release versions. Debug Attribute DebugAttribute debug debug Integer 116 The D Programming Language debug Identifier Two versions of programs are commonly built a release build and a debug build. The debug build includes extra error checking code test harnesses pretty-printing code etc. The debug attribute conditionally compiles in code class Foo int a b debug int flag Conditional Compilation means that if .
