Macro good_lp::variables

macro_rules! variables {
    () => { ... };
}

Instantiates ProblemVariables, to create a set of related variables.

Using a macro allows this crate to give different types to variables that were instantiated at different places in the code.

Working example

use good_lp::variables;

let mut vars = variables!();
let x = vars.add_variable();
let y = vars.add_variable();
let objective = x + y / 2;

Trying to add incompatible variables

You should never create expressions with variabless that come from different ProblemVariables insstances.

use good_lp::variables;

let mut pb1 = variables!();
let mut pb2 = variables!();
let x = pb1.add_variable();
let y = pb2.add_variable();
let objective = x + y / 2;

Since pb1 and pb2 have been instanciated at two different places in the code, they are different problems and their variables are not compatible with one another.