The classical resource-constrained project scheduling problem (RCPSP), a well-known NP-hard problem in scheduling, is one of the most extensively investigated problems in operations research. It has been attracting considerable attention from academia and industry for several decades. Recently, a number of new and promising meta-heuristic approaches for solving the RCPSP problem have emerged. In this paper, we provide a detailed review of the most recent approaches for solving the RCPSP that have been proposed in literature. In particular, we present a comparison, classification and analysis, based on a number of relevant metrics. Extensive numerical results based on well-known benchmark problem instance sets of size J30, J60 and J120 from Project Scheduling Problem Library (PSPLIB), as well as comparisons among state-of-the-art hybrid meta-heuristic algorithms demonstrate the effectiveness of the proposed approaches for solving the RCPSP of various scales.