Mirror/ardupilot
5
0
Fork 0
mirror of https://github.com/ArduPilot/ardupilot synced 2025-01-05 07:28:29 -04:00
Code Issues Packages Projects Releases Wiki Activity

AP_Buffer: change pop_front to return a bool if successful

Browse Source
This commit is contained in:
Jonathan Challinger 2014-10-19 12:28:45 -07:00 committed by Andrew Tridgell
parent ceef10cc41
commit 1c75ce88f2
1 changed files with 13 additions and 16 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
libraries/AP_Buffer/AP_Buffer.h
View File

@ -26,10 +26,11 @@ public:
/// @param item /// @param item
void push_back( const T &item ); void push_back( const T &item );
/// pop_front - removes an element from the begin of the buffer (i.e. the oldest element) /// pop_front - removes an element from the beginning of the
/// and returns it. If the buffer is empty, 0 is returned /// buffer (i.e. the oldest element) and returns it in ret.
/// @return /// @param ret : the removed element, if exists
T pop_front(); /// @return : true if successful, false if not
bool pop_front(T &ret);
/// peek - returns a reference to an element of the buffer /// peek - returns a reference to an element of the buffer
/// if position isn't valid (i.e. >= size()) 0 is returned /// if position isn't valid (i.e. >= size()) 0 is returned
@ -105,20 +106,16 @@ void AP_Buffer<T,SIZE>::push_back( const T &item )
} }
template <class T, uint8_t SIZE> template <class T, uint8_t SIZE>
T AP_Buffer<T,SIZE>::pop_front() bool AP_Buffer<T,SIZE>::pop_front(T &ret)
{ {
T result;
// get next value in buffer
result = _buff[_head];
if(_num_items == 0) { if(_num_items == 0) {
// return whatever is at _head // buffer is empty
// don't return zero because it is a scalar value return false;
// don't return T() because PX4 compiler does not support it
return result;
} }
// get next value in buffer
ret = _buff[_head];
// increment to next point // increment to next point
_head++; _head++;
if( _head >= SIZE ) if( _head >= SIZE )
@ -127,8 +124,8 @@ T AP_Buffer<T,SIZE>::pop_front()
// reduce number of items // reduce number of items
_num_items--; _num_items--;
// return item // success
return result; return true;
} }
template <class T, uint8_t SIZE> template <class T, uint8_t SIZE>