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Eigen  3.4.99 (git rev 10c77b0ff44d0b9cb0b252cfa0ccaaa39d3c5da4)
Eigen::symbolic Namespace Reference


class  BaseExpr
class  SymbolExpr
class  SymbolValue

Detailed Description

This namespace defines a set of classes and functions to build and evaluate symbolic expressions of scalar type Index. Here is a simple example:

// First step, defines symbols:
struct x_tag {}; static const symbolic::SymbolExpr<x_tag> x;
struct y_tag {}; static const symbolic::SymbolExpr<y_tag> y;
struct z_tag {}; static const symbolic::SymbolExpr<z_tag> z;
// Defines an expression:
auto expr = (x+3)/y+z;
// And evaluate it: (c++14)
std::cout << expr.eval(x=6,y=3,z=-13) << "\n";
// In c++98/11, only one symbol per expression is supported for now:
auto expr98 = (3-x)/2;
std::cout << expr98.eval(x=6) << "\n";

It is currently only used internally to define and manipulate the Eigen::last and Eigen::lastp1 symbols in Eigen::seq and Eigen::seqN.