Here are the classes, structs, unions and interfaces with brief descriptions:

[detail level 123]

Bonmin
Couenne	General include file for different compilers
CouenneAggrProbing	Cut Generator for aggressive BT; i.e., an aggressive probing
CouenneBTPerfIndicator
CouenneFixPoint	Cut Generator for FBBT fixpoint
CouenneMultiVarProbe
CouenneSparseBndVec
CouenneTwoImplied	Cut Generator for implied bounds derived from pairs of linear (in)equalities
CouenneBranchingObject	"Spatial" branching object
CouenneSolverInterface	Solver interface class with a pointer to a Couenne cut generator
CouenneChooseStrong
CouenneChooseVariable	Choose a variable for branching
CouenneComplBranchingObject	"Spatial" branching object for complementarity constraints
CouenneComplObject	OsiObject for complementarity constraints $x_1 x_2 \ge,\le,= 0$
CouenneObject	OsiObject for auxiliary variables $w=f(x)$
CouenneOrbitBranchingObj	"Spatial" branching object
CouenneSOSBranchingObject
CouenneSOSObject
CouenneThreeWayBranchObj	Spatial, three-way branching object
CouenneVarObject	OsiObject for variables in a MINLP
CouenneVTObject	OsiObject for violation transfer on variables in a MINLP
CouenneCutGenerator	Cut Generator for linear convexifications
AuxRelation	Base class definition for relations between auxiliaries
SumLogAuxRel	Identifies 5-ples of variables of the form
MultiProdRel	Identifies 5-ples of variables of the form
BiProdDivRel	Identifies 5-tuple of the form
PowRel	Identifies 5-tuple of the form
CouenneCrossConv	Cut Generator that uses relationships between auxiliaries
CouenneScalar
CouenneSparseVector
compare_scalars
CouenneExprMatrix
compare_pair_ind
CouennePSDcon	Class to represent positive semidefinite constraints //////////////////
CouenneSdpCuts	These are cuts of the form
CouenneDisjCuts	Cut Generator for linear convexifications
DomainPoint	Define a point in the solution space and the bounds around it
Domain	Define a dynamic point+bounds, with a way to save and restore previous points+bounds through a LIFO structure
exprAux	Auxiliary variable
compExpr	Structure for comparing expressions
exprLowerBound	These are bound expression classes
exprUpperBound	Upper bound
exprClone	Expression clone (points to another expression)
exprConst	Constant-type operator
exprCopy
expression	Expression base class
exprIVar	Variable-type operator
exprOp	General n-ary operator-type expression: requires argument list
exprStore	Storage class for previously evaluated expressions
exprUnary	Expression class for unary functions (sin, log, etc.)
exprVar	Variable-type operator
t_chg_bounds	Status of lower/upper bound of a variable, to be checked/modified in bound tightening
CouExpr
exprLBCos	Class to compute lower bound of a cosine based on the bounds of its arguments
exprUBCos	Class to compute lower bound of a cosine based on the bounds of its arguments
exprLBDiv	Class to compute lower bound of a fraction based on the bounds of both numerator and denominator
exprUBDiv	Class to compute upper bound of a fraction based on the bounds of both numerator and denominator
exprLBMul	Class to compute lower bound of a product based on the bounds of both factors
exprUBMul	Class to compute upper bound of a product based on the bounds of both factors
exprLBQuad	Class to compute lower bound of a fraction based on the bounds of both numerator and denominator
exprUBQuad	Class to compute upper bound of a fraction based on the bounds of both numerator and denominator
exprLBSin	Class to compute lower bound of a sine based on the bounds on its arguments
exprUBSin	Class to compute lower bound of a sine based on the bounds on its arguments
exprAbs	Class for
exprBinProd	Class for $\prod_{i=1}^n f_i(x)$ with all binary
exprCeil	Class ceiling, $\lceil f(x) \rceil$
exprCos	Class cosine, $\cos f(x)$
exprDiv	Class for divisions, $\frac{f(x)}{g(x)}$
exprEvenPow	Power of an expression (binary operator) with even exponent, with $k\in \mathbb Z$ constant even
exprExp	Class for the exponential, $e^{f(x)}$
exprFloor	Class floor, $\lfloor f(x) \rfloor$
exprGroup	Class Group, with constant, linear and nonlinear terms: $a_0 + \sum_{i=1}^n a_i x_i$
exprIf
exprInv	Class inverse:
exprLog	Class logarithm, $\log f(x)$
exprMax
exprMin
exprMul	Class for multiplications, $\prod_{i=1}^n f_i(x)$
exprMultiLin	Another class for multiplications, $\prod_{i=1}^n f_i(x)$
exprNorm	Class for -norms, $\|\| f(x)\|\|_p = \left(\sum_{i=1}^n f_i(x)^p\right)^{\frac{1}{p}}$
exprOddPow	Power of an expression (binary operator), with constant
exprOpp	Class opposite,
exprPow	Power of an expression (binary operator), with constant
exprPWLinear
exprQuad	Class exprQuad, with constant, linear and quadratic terms
exprSignPow	Power of an expression (binary operator), $f(x)\|f(x)\|^{k-1}$ with $k \in \mathbb R$ constant
exprSin	Class for $\sin f(x)$
exprSub	Class for subtraction,
exprSum	Class sum, $\sum_{i=1}^n f_i(x)$
exprTrilinear	Class for multiplications
ExprHess	Expression matrices
ExprJac	Jacobian of the problem (computed through Couenne expression classes)
InitHeuristic	A heuristic that stores the initial solution of the NLP
NlpSolveHeuristic
CouenneFeasPump	An implementation of the Feasibility pump that uses linearization and Ipopt to find the two sequences of points
CouenneFPsolution	Class containing a solution with infeasibility evaluation
compareSol	Class for comparing solutions (used in tabu list)
CouenneFPpool	Pool of solutions
CouenneIterativeRounding	An iterative rounding heuristic, tailored for nonconvex MINLPs
CouenneInterface
CouenneMINLPInterface	This is class provides an Osi interface for a Mixed Integer Linear Program expressed as a TMINLP (so that we can use it for example as the continuous solver in Cbc)
CouenneTNLP	Class for handling NLPs using CouenneProblem
CouenneUserInterface
CouenneInfo	Bonmin class for passing info between components of branch-and-cuts
NlpSolution	Class for storing an Nlp Solution
SmartAsl
CouenneSetup
CouenneBab
CouenneOSInterface
GlobalCutOff
CouenneProblem	Class for MINLP problems with symbolic information
CouenneConstraint	Class to represent nonlinear constraints
CouenneObjective	Objective function
CouenneRecordBestSol
compNode	Structure for comparing nodes in the dependence graph
DepNode	Vertex of a dependence graph
DepGraph	Dependence graph
CouenneAmplInterface
quadElem
LinMap
QuadMap
funtriplet
simpletriplet
powertriplet
kpowertriplet
Qroot	Class that stores result of previous calls to rootQ into a map for faster access
CouenneSparseMatrix	Class for sparse Matrixs (used in modifying distances in FP)
Ipopt
SmartPtr
Osi
less_than_str
myclass
myclass0
Nauty
Node