We recommend to use the strumpack::structured::StructuredMatrix interface instead of directly using the BLR classes. See Dense Solvers .
The BLR code can be found in the src/BLR/ subdirectory. All BLR code is in a namespace called BLR.
The class for a sequential/multithreaded BLR matrix is BLRMatrix<scalar>.
Distributed memory BLR support is implemented in the BLRMatrixMPI<scalar> class.