Module syntex_syntax::feature_gate 
                   
                       [−]
                   
               [src]
Feature gating
This module implements the gating necessary for preventing certain compiler features from being used by default. This module will crawl a pre-expanded AST to ensure that there are no features which are used that are not enabled.
Features are enabled in programs via the crate-level attributes of
#![feature(...)] with a comma-separated list of features.
For the purpose of future feature-tracking, once code for detection of feature gate usage is added, do not remove it again even once the feature becomes stable.
Structs
| Features | A set of features to be used by later passes. | 
| GatedCfg | 
Enums
| AttributeGate | |
| AttributeType | |
| GateIssue | |
| GatedCfgAttr | |
| UnstableFeatures | 
Constants
| EXPLAIN_ALLOW_INTERNAL_UNSTABLE | |
| EXPLAIN_ASM | |
| EXPLAIN_CONCAT_IDENTS | |
| EXPLAIN_CUSTOM_DERIVE | |
| EXPLAIN_LOG_SYNTAX | |
| EXPLAIN_TRACE_MACROS | |
| KNOWN_ATTRIBUTES | 
Functions
| check_crate | |
| check_crate_macros | |
| check_for_box_syntax | |
| check_for_placement_in | |
| check_for_pushpop_syntax | |
| emit_feature_err |