How to compute volume of TopoDS_Shape / TopoDS_Solid in OpenCASCADE

OCCUtils provides a convenience function to do this:

#include <occutils/Shape.hxx>

using namespace OCCUtils;

TopoDS_Shape myShape = /* ... */;

double volume = Shape::Volume(myShape);

In case you need to do this without OCCUtils, use

GProp_GProps gprops;
BRepGProp::VolumeProperties(shape, gprops);
double volume = gprops.Mass();