MPD  0.20.6
VarSize.hxx
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1 /*
2  * Copyright (C) 2008-2014 Max Kellermann <max.kellermann@gmail.com>
3  *
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29 
30 #ifndef MPD_VAR_SIZE_HXX
31 #define MPD_VAR_SIZE_HXX
32 
33 #include "Alloc.hxx"
34 #include "Compiler.h"
35 
36 #include <type_traits>
37 #include <utility>
38 #include <new>
39 #include <cstdlib>
40 
52 template<class T, typename... Args>
54 T *
55 NewVarSize(size_t declared_tail_size, size_t real_tail_size, Args&&... args)
56 {
57  static_assert(std::is_standard_layout<T>::value,
58  "Not standard-layout");
59 
60  /* determine the total size of this instance */
61  size_t size = sizeof(T) - declared_tail_size + real_tail_size;
62 
63  /* allocate memory */
64  T *instance = (T *)xalloc(size);
65 
66  /* call the constructor */
67  new(instance) T(std::forward<Args>(args)...);
68 
69  return instance;
70 }
71 
72 template<typename T>
74 void
76 {
77  /* call the destructor */
78  instance->T::~T();
79 
80  /* free memory */
81  free(instance);
82 }
83 
84 #endif
#define gcc_nonnull_all
Definition: Compiler.h:122
#define gcc_malloc
Definition: Compiler.h:112
gcc_malloc void * xalloc(size_t size)
Allocate memory.
Instance * instance
gcc_nonnull_all void DeleteVarSize(T *instance)
Definition: VarSize.hxx:75
gcc_malloc T * NewVarSize(size_t declared_tail_size, size_t real_tail_size, Args &&...args)
Allocate and construct a variable-size object.
Definition: VarSize.hxx:55