Macro.h File Reference

Detailed Description

Helper macros.

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Macros
#define	DISALLOW_COPY_AND_ASSIGN(TypeName)
	Creates dummy copy constructor and assignment operator declarations. More...
#define	OLA_UNUSED
	Mark unused arguments & types. More...
#define	OLA_FALLTHROUGH
	Mark switch cases as fallthrough when required. More...
#define	STATIC_ASSERT(x)   extern int __dummy[static_cast<int>x]
	Compile time assert(). More...
#define	PACK(__Declaration__)   __Declaration__ __attribute__((__packed__))
	Pack structures. More...

Macro Definition Documentation

#define DISALLOW_COPY_AND_ASSIGN

(

TypeName

)

Value:

TypeName(const TypeName&);               \
  void operator=(const TypeName&)

Creates dummy copy constructor and assignment operator declarations.

Use this in the private: section of a class to prevent copying / assignment.

Example

class Foo {
  public:
    Foo() { ... }

  private:
    DISALLOW_COPY_AND_ASSIGN(Foo);
  };

#define OLA_FALLTHROUGH

Mark switch cases as fallthrough when required.

Note

We are not currently using [[fallthrough]]; because we need C++98 compatibility

Example

switch (cond) {
  case 'foo':
    doFoo();
    // after foo fallthrough to bar because $REASON
    OLA_FALLTHROUGH
  case 'bar':

#define OLA_UNUSED

Mark unused arguments & types.

Example

void Foo(OLA_UNUSED int bar) {}

OLA_UNUSED typedef int Baz;

#define PACK

(

__Declaration__

)

__Declaration__ __attribute__((__packed__))

Pack structures.

In order to account for platform differences with regard to packing, we need to use the following macro while declaring types that need to have a specific binary layout. Taken from: http://stackoverflow.com/questions/1537964/ visual-c-equivalent-of-gccs-attribute-packed

Example

PACK(
struct foo_s {
  uint16_t bar;
});

#define STATIC_ASSERT

(

x

)

extern int __dummy[static_cast<int>x]

Compile time assert().

Example

PACK(
struct foo_s {
  uint16_t bar;
});
STATIC_ASSERT(sizeof(foo_s) == 2);