Function Z3_ast_vector_set 

pub unsafe extern "C" fn Z3_ast_vector_set(
    c: Z3_context,
    v: Z3_ast_vector,
    i: c_uint,
    a: Z3_ast,
)

Update position i of the AST vector v with the AST a.

Preconditions:

• i < Z3_ast_vector_size(c, v)