Function z3_sys::Z3_mk_seq_index

pub unsafe extern "C" fn Z3_mk_seq_index(
    c: Z3_context,
    s: Z3_ast,
    substr: Z3_ast,
    offset: Z3_ast
) -> Z3_ast

Return index of first occurrence of substr in s starting from offset offset. If s does not contain substr, then the value is -1, if offset is the length of s, then the value is -1 as well. The function is under-specified if offset is negative or larger than the length of s.