diff options
Diffstat (limited to 'core')
| -rw-r--r-- | core/qthelper.h | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/core/qthelper.h b/core/qthelper.h index a2decd527..e1517991c 100644 --- a/core/qthelper.h +++ b/core/qthelper.h @@ -88,6 +88,32 @@ QString getUserAgent(); #define TITLE_OR_TEXT(_t, _m) _t, _m #endif +// Move a range in a vector to a different position. +// The parameters are given according to the usual STL-semantics: +// v: a container with STL-like random access iterator via std::begin(...) +// rangeBegin: index of first element +// rangeEnd: index one *past* last element +// destination: index to element before which the range will be moved +// Owing to std::begin() magic, this function works with STL-like containers: +// QVector<int> v{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; +// moveInVector(v, 1, 4, 6); +// as well as with C-style arrays: +// int array[10] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 }; +// moveInVector(array, 1, 4, 6); +// Both calls will have the following effect: +// Before: 0 1 2 3 4 5 6 7 8 9 +// After: 0 4 5 1 2 3 6 7 8 9 +// No sanitizing of the input arguments is performed. +template <typename Vector> +void moveInVector(Vector &v, int rangeBegin, int rangeEnd, int destination) +{ + auto it = std::begin(v); + if (destination > rangeEnd) + std::rotate(it + rangeBegin, it + rangeEnd, it + destination); + else if (destination < rangeBegin) + std::rotate(it + destination, it + rangeBegin, it + rangeEnd); +} + #endif // 3) Functions visible to C and C++ |