Function lv2_raw::coreutils::lv2_features_query
[−]
[src]
pub unsafe fn lv2_features_query(
features: *const *const LV2Feature,
query: &[FeatureHelper]
) -> *const c_char
Query a features array.
This function allows getting several features in one call, and detect missing required features, with the same caveat of lv2_features_data().
The arguments should be a series of const char* uri, void** data, bool required, terminated by a NULL URI. The data pointers MUST be initialized to NULL. For example:
@code LV2_URID_Log* log = NULL; LV2_URID_Map* map = NULL; const char* missing = lv2_features_query( features, LV2_LOG__log, &log, false, LV2_URID__map, &map, true, NULL); @endcode
@return NULL on success, otherwise the URI of this missing feature.