Installation¶

Requirements¶

• GCC 14 or Clang 18 / C++23. MIP++ targets GCC 14 / C++23, though its original target — GCC 15 / C++26 — remains the recommended toolchain. A handful of C++26 features it relies on (such as std::views::concat and std::flat_map) are provided by built-in fallbacks, so GCC 14 or Clang 18 in C++23 mode is enough to build it. Clang is tested against libstdc++.
• dylib 3.0 — the only library dependency, used to load solver shared libraries at runtime. It is pulled in automatically when using Conan.
• At least one solver installed on the machine that runs your program (see below). Nothing is needed at compile time.

MIP++ is header-only: there is nothing to build, and your binary never links against a solver SDK.

Getting the headers¶

git clone https://github.com/fhamonic/mippp && cd mippp
conan create . -u -b=missing -pr=<your_conan_profile>

add_subdirectory(dependencies/mippp)
target_link_libraries(<target> INTERFACE mippp)

Making solver libraries discoverable¶

Each <solver>_api object locates and loads the solver's shared library when it is constructed. Resolution proceeds in this order — first match wins:

1. An explicit path given to the api constructor: highs_api api("/path/to/libhighs.so"); loads exactly that file.

2. The MIPPP_<SOLVER>_LIBRARY environment variable, used verbatim as the full path of the library file. This is the way to pin an exact file when several versions are installed, or when only a version-suffixed soname exists:

   export MIPPP_HIGHS_LIBRARY="/path/to/HiGHS/build/lib/libhighs.so.1.10.0"
   

   Recognized keys: GUROBI, CPLEX, XPRESS, MOSEK, COPT, SCIP, HIGHS, SOPLEX, CLP, CBC, GLPK.

3. The dynamic loader's search directories — LD_LIBRARY_PATH and the system library directories on Linux (with /etc/ld.so.conf honored), DYLD_LIBRARY_PATH and the usual locations on macOS, PATH on Windows. The conventional decorated name (libhighs.so) is preferred; if only version-suffixed variants exist (libhighs.so.1.10.0), the lexicographically greatest filename — usually the highest version — is picked.

Solvers installed through the system package manager (e.g. apt install coinor-clp coinor-libclp-dev libglpk-dev) are found without any configuration. Commercial and source-built solvers usually live outside the system directories, so export their locations from your shell profile, adjusting the base paths to your installation:

# Gurobi
export GUROBI_HOME="/path/to/solvers/gurobi1201/linux64"
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$GUROBI_HOME/lib"

# HiGHS
export HIGHS_HOME="/path/to/solvers/HiGHS"
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$HIGHS_HOME/lib"

# CPLEX
export CPLEX_STUDIO_BINARIES="/path/to/solvers/cplex-community/cplex/bin/x86-64_linux"
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$CPLEX_STUDIO_BINARIES"

# FICO Xpress (also needs its license variable)
export XPRESS_HOME="/path/to/solvers/xpressmp"
export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$XPRESS_HOME/lib"
export XPAUTH_PATH="$XPRESS_HOME/bin"

(The same pattern applies to COPT, MOSEK, and COIN-OR builds — see CONTRIBUTING.md for the full list.)

Only export the solvers you actually have. If a library cannot be located, the api constructor throws a std::runtime_error naming the files it tried and the environment variable to set.

Checking that everything works¶

Build and run any of the examples — the smallest is simple_lp.cpp, which uses HiGHS. If you cloned the repository, the test suite can also be run with make CONAN_PROFILE=<your_profile>, and restricted to one backend with make test highs CONAN_PROFILE=<your_profile>; backends whose runtime library is missing are skipped automatically.

Next¶

A first model — the two-variable LP, line by line.