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Diffstat (limited to 'src')
| -rw-r--r-- | src/libcamera/utils.cpp | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/src/libcamera/utils.cpp b/src/libcamera/utils.cpp index c4098a74..826144d3 100644 --- a/src/libcamera/utils.cpp +++ b/src/libcamera/utils.cpp @@ -472,6 +472,40 @@ std::string libcameraSourcePath() * loop, will cause the loop to iterate over the \a iterable in reverse order */ +/** + * \fn enumerate(T &iterable) + * \brief Wrap an iterable to enumerate index and value in a range-based loop + * \param[in] iterable The iterable + * + * Range-based for loops are handy and widely preferred in C++, but are limited + * in their ability to replace for loops that require access to a loop counter. + * The enumerate() function solves this problem by wrapping the \a iterable in + * an adapter that, when used as a range-expression, will provide iterators + * whose value_type is a pair of index and value reference. + * + * The iterable must support std::begin() and std::end(). This includes all + * containers provided by the standard C++ library, as well as C-style arrays. + * + * A typical usage pattern would use structured binding to store the index and + * value in two separate variables: + * + * \code{.cpp} + * std::vector<int> values = ...; + * + * for (auto [index, value] : utils::enumerate(values)) { + * ... + * } + * \endcode + * + * Note that the argument to enumerate() has to be an lvalue, as the lifetime + * of any rvalue would not be extended to the whole for loop. The compiler will + * complain if an rvalue is passed to the function, in which case it should be + * stored in a local variable before the loop. + * + * \return A value of unspecified type that, when used in a range-based for + * loop, iterates over an indexed view of the \a iterable + */ + } /* namespace utils */ } /* namespace libcamera */ |