v2.31.0 (21 November 2022)

• Improved the error message for bad multiple declarations. (#1239)
• Fixed a bug where using a C++ reserved word as a name in certain situations would prevent compilation. (#1243)
• Build binaries in parallel on Jenkins. (#1244)
• Added functions complex_schur_decompose_t() and complex_schur_decompose_u() implementing the complex-valued Schur decomposition for matrices.(#1247)
• Vectorized the conj function for complex types.(#1253)
• CI change, build backwards-compatible Mac executables on flatiron mac. (#1255)
• Improved the error generated when a function is re-declared, or when a function is not given a definition. (#1256)
• print and reject will now be listed as functions in stanc --infos output. (#1257)
• Added quantile functions (inverse-CDFs) std_normal_qf and std_normal_log_qf. std_normal_qf is a synonym for inv_Phi, and std_normal_log_qf is the same but with the input on the log-scale.(#1258)
• Fix using reject() with container types. (#1261)
• Vectorized sampling statements can now be used with the truncation syntax T[ , ](#1263)
• Functions which return integer types are considered as "data" for purposes of data-only arguments.(#1265)
• The negation operator - can now accept arrays, e.g. array[N] int foo = {...}; print(-foo);(#1266)
• Exposes algebraic functions with a variadic arguments, using the following four functions: solve_powell, solve_powell_tol, solve_newton and solve_newton_tol. Relevant changes to Stan-math are already merged.(#1268)