Difference between revisions of "Calypso/TipsAndTricks"
(→Constructing C++ classes or structs on malloc'd memory) |
m (→Constructing C++ classes or structs on malloc'd memory) |
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| − | == Constructing C++ classes or structs | + | == Constructing C++ classes or structs inside malloc'd memory == |
| − | When a C++ library expects to be granted ownership | + | When a C++ library expects to be granted ownership of a piece of memory, the allocation shouldn't be done by the GC unless you always keep a reference to the allocated memory, which is pointless additional work and not always possible. |
| − | Calypso provides a small runtime library which contains some | + | Calypso provides a small runtime library which contains some commonplace utility functions, such as <code>cppNew</code> and <code>cppDelete</code> to bypass the GC while constructing C++ class/struct objects: |
<syntaxhighlight lang="D"> | <syntaxhighlight lang="D"> | ||
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import (C++) std.unique_ptr; | import (C++) std.unique_ptr; | ||
| − | auto testClass = cppNew!MyCppClass(); // malloc then ctor call | + | auto testClass = cppNew!MyCppClass(...); // malloc then ctor call |
unique_ptr!MyCppClass owner; | unique_ptr!MyCppClass owner; | ||
owner.reset(testClass); | owner.reset(testClass); | ||
Revision as of 21:02, 27 June 2016
Constructing C++ classes or structs inside malloc'd memory
When a C++ library expects to be granted ownership of a piece of memory, the allocation shouldn't be done by the GC unless you always keep a reference to the allocated memory, which is pointless additional work and not always possible.
Calypso provides a small runtime library which contains some commonplace utility functions, such as cppNew and cppDelete to bypass the GC while constructing C++ class/struct objects:
import cpp.memory; // cppNew and cppDelete
import (C++) std.unique_ptr;
auto testClass = cppNew!MyCppClass(...); // malloc then ctor call
unique_ptr!MyCppClass owner;
owner.reset(testClass);
// testClass will be free'd by the owner's dtor
