$ g++ -march=native -O3 -fPIC -fno-strict-aliasing -fexceptions -DNDEBUG -DIL_STD -I/opt/ibm/ILOG/CPLEX_Studio126/cplex/include -I/opt/ibm/ILOG/CPLEX_Studio126/concert/include -L/opt/ibm/ILOG/CPLEX_Studio126/cplex/lib/x86-64_linux/static_pic -L/opt/ibm/ILOG/CPLEX_Studio126/concert/lib/x86-64_linux/static_pic -lconcert -lilocplex -lcplex -lm -lpthread heu.o cplex.o brute_force.o -o heu
cplex.o: In function `find_cplex(unsigned char*)':
cplex.cpp:(.text+0x39): undefined reference to `IloEnv::IloEnv()'
cplex.cpp:(.text+0x58): undefined reference to `IloModel::IloModel(IloEnv, char const*)'
cplex.cpp:(.text+0x8e): undefined reference to `IloArrayI::IloArrayI(IloGenAlloc*, long, long)'
cplex.cpp:(.text+0x106): undefined reference to `IloArrayI::IloArrayI(IloGenAlloc*, long, long)'
cplex.cpp:(.text+0x16d): undefined reference to `IloIntVarArray::IloIntVarArray(IloEnv, long, long, long)'
cplex.cpp:(.text+0x203): undefined reference to `IloExtractableI::setName(char const*)'
cplex.cpp:(.text+0x263): undefined reference to `IloArrayI::IloArrayI(IloGenAlloc*, long, long)'
cplex.cpp:(.text+0x2bb): undefined reference to `IloIntVarArray::IloIntVarArray(IloEnv, long, long, long)'
cplex.cpp:(.text+0x332): undefined reference to `IloExtractableI::setName(char const*)'
cplex.cpp:(.text+0x364): undefined reference to `IloIntExpr::IloIntExpr(IloEnv, long)'
cplex.cpp:(.text+0x3a8): undefined reference to `IloSum(IloIntVarArray)'
cplex.cpp:(.text+0x3b3): undefined reference to `IloIntExpr::operator+=(IloIntExprArg)'
cplex.cpp:(.text+0x3ef): undefined reference to `operator>=(IloNumExprArg, double)'
cplex.cpp:(.text+0x41e): undefined reference to `IloModel::add(IloExtractable) const'
cplex.cpp:(.text+0x498): undefined reference to `IloIntExpr::IloIntExpr(IloEnv, long)'
cplex.cpp:(.text+0x5a9): undefined reference to `operator+(IloIntExprArg, IloIntExprArg)'
cplex.cpp:(.text+0x5b8): undefined reference to `IloIntExpr::operator+=(IloIntExprArg)'
cplex.cpp:(.text+0x61a): undefined reference to `operator*(int, IloIntVar)'
cplex.cpp:(.text+0x631): undefined reference to `IloIntLinExprTerm::operator IloIntExprArg() const'
cplex.cpp:(.text+0x665): undefined reference to `operator>=(IloNumExprArg, IloNumExprArg)'
cplex.cpp:(.text+0x68c): undefined reference to `IloModel::add(IloExtractable) const'
cplex.cpp:(.text+0x6f3): undefined reference to `operator*(int, IloIntVar)'
cplex.cpp:(.text+0x70a): undefined reference to `IloIntLinExprTerm::operator IloIntExprArg() const'
cplex.cpp:(.text+0x72e): undefined reference to `operator>=(IloNumExprArg, IloNumExprArg)'
cplex.cpp:(.text+0x750): undefined reference to `IloModel::add(IloExtractable) const'
cplex.cpp:(.text+0x847): undefined reference to `operator>=(IloNumExprArg, IloNumExprArg)'
cplex.cpp:(.text+0x86b): undefined reference to `IloModel::add(IloExtractable) const'
cplex.cpp:(.text+0x8a9): undefined reference to `IloIntExpr::IloIntExpr(IloEnv, long)'
cplex.cpp:(.text+0x92d): undefined reference to `IloIntExpr::operator+=(IloIntExprArg)'
cplex.cpp:(.text+0x96b): undefined reference to `IloEnvI::matchesAllocatorThread() const'
cplex.cpp:(.text+0x9b6): undefined reference to `IloObjectiveI::IloObjectiveI(IloEnvI*, IloNumExprI*, IloObjective::Sense, char const*)'
cplex.cpp:(.text+0x9d5): undefined reference to `IloModel::add(IloExtractable) const'
cplex.cpp:(.text+0x9f5): undefined reference to `IloCplex::IloCplex(IloModel)'
cplex.cpp:(.text+0xa0c): undefined reference to `IloAlgorithm::setOut(std::ostream&)'
cplex.cpp:(.text+0xa23): undefined reference to `IloAlgorithm::setWarning(std::ostream&)'
cplex.cpp:(.text+0xa2b): undefined reference to `IloAlgorithm::solve() const'
cplex.cpp:(.text+0xa48): undefined reference to `IloEnvI::~IloEnvI()'
cplex.cpp:(.text+0xa98): undefined reference to `IloAlgorithm::getValue(IloNumExprArg) const'
cplex.cpp:(.text+0xaec): undefined reference to `IloAllocationList::alloc(long)'
cplex.cpp:(.text+0xb00): undefined reference to `IloAllocationList::alloc(long)'
cplex.cpp:(.text+0xb23): undefined reference to `IloFixedSizeAllocatorI::allocateBlock(IloMemory*)'
cplex.cpp:(.text+0xb95): undefined reference to `IloEnvAllocatorThreadMismatch::IloEnvAllocatorThreadMismatch()'
cplex.cpp:(.text+0xb9c): undefined reference to `IloEnvAllocatorThreadMismatch::~IloEnvAllocatorThreadMismatch()'
cplex.cpp:(.text+0xba6): undefined reference to `typeinfo for IloEnvAllocatorThreadMismatch'
cplex.cpp:(.text+0xc7c): undefined reference to `IloEnvAllocationDisabled::IloEnvAllocationDisabled()'
cplex.cpp:(.text+0xc83): undefined reference to `IloEnvAllocationDisabled::~IloEnvAllocationDisabled()'
cplex.cpp:(.text+0xc8d): undefined reference to `typeinfo for IloEnvAllocationDisabled'
cplex.o:(.data.DW.ref._ZTI12IloException[DW.ref._ZTI12IloException]+0x0): undefined reference to `typeinfo for IloException'
collect2: error: ld returned 1 exit status