| assert_all_are_classes | Is the input the name of a (formally defined) class? | 
| assert_any_are_classes | Is the input the name of a (formally defined) class? | 
| assert_is_all_of | Does x belong to these classes? | 
| assert_is_any_of | Does x belong to these classes? | 
| assert_is_an_integer | Is the input an integer? | 
| assert_is_array | Is the input an array or matrix? | 
| assert_is_a_bool | Is the input logical? | 
| assert_is_a_complex | Is the input complex? | 
| assert_is_a_double | Is the input numeric? | 
| assert_is_a_number | Is the input numeric? | 
| assert_is_a_raw | Is the input raw? | 
| assert_is_a_string | Is the input of type character? | 
| assert_is_builtin_function | Is the input a closure, builtin or special function? | 
| assert_is_call | Is the input a language object? | 
| assert_is_character | Is the input of type character? | 
| assert_is_closure_function | Is the input a closure, builtin or special function? | 
| assert_is_complex | Is the input complex? | 
| assert_is_condition | Is the input a condition? | 
| assert_is_data.frame | Is the input is a data.frame? | 
| assert_is_data.table | Is the input a data.table? | 
| assert_is_date | Is the input a date? | 
| assert_is_double | Is the input numeric? | 
| assert_is_environment | Is the input an environment? | 
| assert_is_error | Is the input a condition? | 
| assert_is_expression | Is the input a language object? | 
| assert_is_externalptr | Is the input is an external pointer? | 
| assert_is_factor | Is the input a factor? | 
| assert_is_formula | Is the input a formula? | 
| assert_is_function | Is the input a function? | 
| assert_is_inherited_from | Does the object inherit from some class? | 
| assert_is_integer | Is the input an integer? | 
| assert_is_internal_function | Is the input an internal function? | 
| assert_is_language | Is the input a language object? | 
| assert_is_leaf | Is the input a (dendrogram) leaf? | 
| assert_is_list | Is the input a list? | 
| assert_is_logical | Is the input logical? | 
| assert_is_matrix | Is the input an array or matrix? | 
| assert_is_message | Is the input a condition? | 
| assert_is_mts | Is the input a time series? | 
| assert_is_name | Is the input a language object? | 
| assert_is_numeric | Is the input numeric? | 
| assert_is_one_sided_formula | Is the input a formula? | 
| assert_is_ordered | Is the input a factor? | 
| assert_is_pairlist | Is the input a list? | 
| assert_is_posixct | Is the input a date? | 
| assert_is_posixlt | Is the input a date? | 
| assert_is_primitive | Is the input a function? | 
| assert_is_qr | Is the input a QR decomposition of a matrix? | 
| assert_is_raster | Is the input a raster? | 
| assert_is_raw | Is the input raw? | 
| assert_is_ref_class_generator | Is the input an S4 object? | 
| assert_is_ref_class_object | Is the input an S4 object? | 
| assert_is_relistable | Is the input relistable? | 
| assert_is_s3_generic | Is the input an S3 generic or method? | 
| assert_is_s3_group_generic | Is the input an S3 generic or method? | 
| assert_is_s3_internal_generic | Is the input an S3 generic or method? | 
| assert_is_s3_method | Is the input an S3 generic or method? | 
| assert_is_s3_primitive_generic | Is the input an S3 generic or method? | 
| assert_is_S4 | Is the input an S4 object? | 
| assert_is_s4 | Is the input an S4 object? | 
| assert_is_s4_group_generic | Is the input an S3 generic or method? | 
| assert_is_simple_error | Is the input a condition? | 
| assert_is_simple_message | Is the input a condition? | 
| assert_is_simple_warning | Is the input a condition? | 
| assert_is_special_function | Is the input a closure, builtin or special function? | 
| assert_is_stepfun | Is the input a function? | 
| assert_is_symbol | Is the input a language object? | 
| assert_is_table | Is the input a table? | 
| assert_is_tbl | Is the input a tbl? | 
| assert_is_tbl_cube | Is the input a tbl? | 
| assert_is_tbl_df | Is the input a tbl? | 
| assert_is_tbl_dt | Is the input a tbl? | 
| assert_is_try_error | Is the input a condition? | 
| assert_is_ts | Is the input a time series? | 
| assert_is_tskernel | Is the input a time series? | 
| assert_is_two_sided_formula | Is the input a formula? | 
| assert_is_warning | Is the input a condition? | 
| is_an_integer | Is the input an integer? | 
| is_array | Is the input an array or matrix? | 
| is_a_bool | Is the input logical? | 
| is_a_complex | Is the input complex? | 
| is_a_double | Is the input numeric? | 
| is_a_number | Is the input numeric? | 
| is_a_raw | Is the input raw? | 
| is_a_string | Is the input of type character? | 
| is_builtin_function | Is the input a closure, builtin or special function? | 
| is_call | Is the input a language object? | 
| is_character | Is the input of type character? | 
| is_class | Is the input the name of a (formally defined) class? | 
| is_closure_function | Is the input a closure, builtin or special function? | 
| is_complex | Is the input complex? | 
| is_condition | Is the input a condition? | 
| is_data.frame | Is the input is a data.frame? | 
| is_data.table | Is the input a data.table? | 
| is_date | Is the input a date? | 
| is_double | Is the input numeric? | 
| is_environment | Is the input an environment? | 
| is_error | Is the input a condition? | 
| is_expression | Is the input a language object? | 
| is_externalptr | Is the input is an external pointer? | 
| is_factor | Is the input a factor? | 
| is_formula | Is the input a formula? | 
| is_function | Is the input a function? | 
| is_inherited_from | Does the object inherit from some class? | 
| is_integer | Is the input an integer? | 
| is_internal_function | Is the input an internal function? | 
| is_language | Is the input a language object? | 
| is_leaf | Is the input a (dendrogram) leaf? | 
| is_list | Is the input a list? | 
| is_logical | Is the input logical? | 
| is_matrix | Is the input an array or matrix? | 
| is_message | Is the input a condition? | 
| is_mts | Is the input a time series? | 
| is_name | Is the input a language object? | 
| is_numeric | Is the input numeric? | 
| is_one_sided_formula | Is the input a formula? | 
| is_ordered | Is the input a factor? | 
| is_pairlist | Is the input a list? | 
| is_posixct | Is the input a date? | 
| is_posixlt | Is the input a date? | 
| is_primitive | Is the input a function? | 
| is_qr | Is the input a QR decomposition of a matrix? | 
| is_raster | Is the input a raster? | 
| is_raw | Is the input raw? | 
| is_ref_class_generator | Is the input an S4 object? | 
| is_ref_class_object | Is the input an S4 object? | 
| is_relistable | Is the input relistable? | 
| is_s3_generic | Is the input an S3 generic or method? | 
| is_s3_group_generic | Is the input an S3 generic or method? | 
| is_s3_internal_generic | Is the input an S3 generic or method? | 
| is_s3_method | Is the input an S3 generic or method? | 
| is_s3_primitive_generic | Is the input an S3 generic or method? | 
| is_S4 | Is the input an S4 object? | 
| is_s4 | Is the input an S4 object? | 
| is_s4_group_generic | Is the input an S3 generic or method? | 
| is_simple_error | Is the input a condition? | 
| is_simple_message | Is the input a condition? | 
| is_simple_warning | Is the input a condition? | 
| is_special_function | Is the input a closure, builtin or special function? | 
| is_stepfun | Is the input a function? | 
| is_symbol | Is the input a language object? | 
| is_table | Is the input a table? | 
| is_tbl | Is the input a tbl? | 
| is_tbl_cube | Is the input a tbl? | 
| is_tbl_df | Is the input a tbl? | 
| is_tbl_dt | Is the input a tbl? | 
| is_try_error | Is the input a condition? | 
| is_ts | Is the input a time series? | 
| is_tskernel | Is the input a time series? | 
| is_two_sided_formula | Is the input a formula? | 
| is_warning | Is the input a condition? |