7 files changed, 131 insertions, 55 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 5114797f0..7dffcd0bc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,7 +2,7 @@
 # It is not intended for manual editing.
 [[package]]
 name = "aho-corasick"
-version = "0.7.4"
+version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -54,7 +54,7 @@ dependencies = [
 
 [[package]]
 name = "backtrace"
-version = "0.3.33"
+version = "0.3.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "backtrace-sys 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -274,7 +274,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.60 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "termios 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "unicode-width 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.3.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -422,7 +422,7 @@ name = "error-chain"
 version = "0.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace 0.3.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -431,7 +431,7 @@ name = "failure"
 version = "0.1.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "backtrace 0.3.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "failure_derive 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -474,7 +474,7 @@ dependencies = [
  "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
  "glob 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "yansi 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -608,7 +608,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "number_prefix 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "parking_lot 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -631,7 +631,7 @@ dependencies = [
 
 [[package]]
 name = "insta"
-version = "0.9.0"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "chrono 0.4.7 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1098,7 +1098,7 @@ dependencies = [
  "rand 0.6.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_chacha 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "rand_xorshift 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -1191,7 +1191,7 @@ dependencies = [
  "chalk-rust-ir 0.1.0 (git+https://github.com/rust-lang/chalk.git)",
  "chalk-solve 0.1.0 (git+https://github.com/rust-lang/chalk.git)",
  "ena 0.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "insta 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "insta 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lalrpop-intern 0.15.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "once_cell 0.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1213,7 +1213,7 @@ version = "0.1.0"
 dependencies = [
  "format-buf 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "fst 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
- "insta 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "insta 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "join_to_string 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1285,7 +1285,7 @@ dependencies = [
 name = "ra_prof"
 version = "0.1.0"
 dependencies = [
- "backtrace 0.3.33 (registry+https://github.com/rust-lang/crates.io-index)",
+ "backtrace 0.3.34 (registry+https://github.com/rust-lang/crates.io-index)",
  "cpuprofiler 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "jemalloc-ctl 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1323,10 +1323,9 @@ dependencies = [
  "ra_parser 0.1.0",
  "ra_rustc_lexer 0.1.0-pre.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "ra_text_edit 0.1.0",
- "rowan 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rowan 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "smol_str 0.1.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "test_utils 0.1.0",
- "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "walkdir 2.2.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -1550,23 +1549,19 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "regex"
-version = "1.2.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "aho-corasick 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "memchr 2.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex-syntax 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)",
  "thread_local 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
- "utf8-ranges 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
 name = "regex-syntax"
-version = "0.6.10"
+version = "0.6.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-dependencies = [
- "ucd-util 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
-]
 
 [[package]]
 name = "relative-path"
@@ -1593,7 +1588,7 @@ dependencies = [
 
 [[package]]
 name = "rowan"
-version = "0.6.1"
+version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1824,7 +1819,7 @@ dependencies = [
  "lazy_static 1.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "pest 2.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "pest_derive 2.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "regex 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde 1.0.98 (registry+https://github.com/rust-lang/crates.io-index)",
  "serde_json 1.0.40 (registry+https://github.com/rust-lang/crates.io-index)",
  "slug 0.1.4 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1917,11 +1912,6 @@ version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "ucd-util"
-version = "0.1.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
 name = "unic-char-property"
 version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2024,11 +2014,6 @@ dependencies = [
 ]
 
 [[package]]
-name = "utf8-ranges"
-version = "1.0.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
-[[package]]
 name = "uuid"
 version = "0.7.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2117,13 +2102,13 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [metadata]
-"checksum aho-corasick 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)" = "36b7aa1ccb7d7ea3f437cf025a2ab1c47cc6c1bc9fc84918ff449def12f5e282"
+"checksum aho-corasick 0.7.6 (registry+https://github.com/rust-lang/crates.io-index)" = "58fb5e95d83b38284460a5fda7d6470aa0b8844d283a0b614b8535e880800d2d"
 "checksum ansi_term 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ee49baf6cb617b853aa8d93bf420db2383fab46d314482ca2803b40d5fde979b"
 "checksum arrayvec 0.4.11 (registry+https://github.com/rust-lang/crates.io-index)" = "b8d73f9beda665eaa98ab9e4f7442bd4e7de6652587de55b2525e52e29c1b0ba"
 "checksum atty 0.2.13 (registry+https://github.com/rust-lang/crates.io-index)" = "1803c647a3ec87095e7ae7acfca019e98de5ec9a7d01343f611cf3152ed71a90"
 "checksum autocfg 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "22130e92352b948e7e82a49cdb0aa94f2211761117f29e052dd397c1ac33542b"
 "checksum backtrace 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "346d7644f0b5f9bc73082d3b2236b69a05fd35cce0cfa3724e184e6a5c9e2a2f"
-"checksum backtrace 0.3.33 (registry+https://github.com/rust-lang/crates.io-index)" = "88fb679bc9af8fa639198790a77f52d345fe13656c08b43afa9424c206b731c6"
+"checksum backtrace 0.3.34 (registry+https://github.com/rust-lang/crates.io-index)" = "b5164d292487f037ece34ec0de2fcede2faa162f085dd96d2385ab81b12765ba"
 "checksum backtrace-sys 0.1.31 (registry+https://github.com/rust-lang/crates.io-index)" = "82a830b4ef2d1124a711c71d263c5abdc710ef8e907bd508c88be475cebc422b"
 "checksum base64 0.10.1 (registry+https://github.com/rust-lang/crates.io-index)" = "0b25d992356d2eb0ed82172f5248873db5560c4721f564b13cb5193bda5e668e"
 "checksum bit-set 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "e84c238982c4b1e1ee668d136c510c67a13465279c0cb367ea6baf6310620a80"
@@ -2192,7 +2177,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum indicatif 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2c60da1c9abea75996b70a931bba6c750730399005b61ccd853cee50ef3d0d0c"
 "checksum inotify 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "40b54539f3910d6f84fbf9a643efd6e3aa6e4f001426c0329576128255994718"
 "checksum inotify-sys 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "e74a1aa87c59aeff6ef2cc2fa62d41bc43f54952f55652656b18a02fd5e356c0"
-"checksum insta 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a915d6263f1d68fc9b693058702a3e9f47f4434dec45d4e35e2b66e490f8bc51"
+"checksum insta 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "00eef45accbe65bfb859ad16649c6b4bed246768d89493473d9ab6c6a0eb908f"
 "checksum iovec 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dbe6e417e7d0975db6512b90796e8ce223145ac4e33c377e4a42882a0e88bb08"
 "checksum itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)" = "5b8467d9c1cebe26feb08c640139247fac215782d35371ade9a2136ed6085358"
 "checksum itoa 0.4.4 (registry+https://github.com/rust-lang/crates.io-index)" = "501266b7edd0174f8530248f87f99c88fbe60ca4ef3dd486835b8d8d53136f7f"
@@ -2268,12 +2253,12 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum rayon-core 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ebbe0df8435ac0c397d467b6cad6d25543d06e8a019ef3f6af3c384597515bd2"
 "checksum rdrand 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "678054eb77286b51581ba43620cc911abf02758c91f93f479767aed0f90458b2"
 "checksum redox_syscall 0.1.56 (registry+https://github.com/rust-lang/crates.io-index)" = "2439c63f3f6139d1b57529d16bc3b8bb855230c8efcc5d3a896c8bea7c3b1e84"
-"checksum regex 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "6b23da8dfd98a84bd7e08700190a5d9f7d2d38abd4369dd1dae651bc40bfd2cc"
-"checksum regex-syntax 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)" = "cd5485bf1523a9ed51c4964273f22f63f24e31632adb5dad134f488f86a3875c"
+"checksum regex 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "88c3d9193984285d544df4a30c23a4e62ead42edf70a4452ceb76dac1ce05c26"
+"checksum regex-syntax 0.6.11 (registry+https://github.com/rust-lang/crates.io-index)" = "b143cceb2ca5e56d5671988ef8b15615733e7ee16cd348e064333b251b89343f"
 "checksum relative-path 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "0e7790c7f1cc73d831d28dc5a7deb316a006e7848e6a7f467cdb10a0a9e0fb1c"
 "checksum remove_dir_all 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "4a83fa3702a688b9359eccba92d153ac33fd2e8462f9e0e3fdf155239ea7792e"
 "checksum ron 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "17f52a24414403f81528b67488cf8edc4eda977d3af1646bb6b106a600ead78f"
-"checksum rowan 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)" = "03e34c2e5f01d7fa4ab7e6a49da44f59fb38ffb61e6c9f714deb8e157274c2c7"
+"checksum rowan 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dc2b79612dedc9004083a61448eb669d336d56690aab29fbd7249e8c8ab41d8c"
 "checksum rustc-demangle 0.1.15 (registry+https://github.com/rust-lang/crates.io-index)" = "a7f4dccf6f4891ebcc0c39f9b6eb1a83b9bf5d747cb439ec6fba4f3b977038af"
 "checksum rustc-hash 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7540fc8b0c49f096ee9c961cda096467dce8084bec6bdca2fc83895fd9b28cb8"
 "checksum rustc_version 0.2.3 (registry+https://github.com/rust-lang/crates.io-index)" = "138e3e0acb6c9fb258b19b67cb8abd63c00679d2851805ea151465464fe9030a"
@@ -2309,7 +2294,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum time 0.1.42 (registry+https://github.com/rust-lang/crates.io-index)" = "db8dcfca086c1143c9270ac42a2bbd8a7ee477b78ac8e45b19abfb0cbede4b6f"
 "checksum typenum 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "612d636f949607bdf9b123b4a6f6d966dedf3ff669f7f045890d3a4a73948169"
 "checksum ucd-trie 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "8f00ed7be0c1ff1e24f46c3d2af4859f7e863672ba3a6e92e7cff702bf9f06c2"
-"checksum ucd-util 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "fa9b3b49edd3468c0e6565d85783f51af95212b6fa3986a5500954f00b460874"
 "checksum unic-char-property 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ce36d3f7ce754afdbccccf8ff0dd0134e50fb44aaae579f96218856e9e5dbd1e"
 "checksum unic-char-range 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "d9ab85fab42ad1b26cafc03bf891f69cb4d6e15f491030e89a0122197baa8ae8"
 "checksum unic-common 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ff8d4a7ade929ef7d971e16ced21a8cd56a63869aa6032dfb8cb083cf7d077bf"
@@ -2324,7 +2308,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc72304796d0818e357ead4e000d19c9c174ab23dc11093ac919054d20a6a7fc"
 "checksum url 1.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "dd4e7c0d531266369519a4aa4f399d748bd37043b00bde1e4ff1f60a120b355a"
 "checksum url_serde 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "74e7d099f1ee52f823d4bdd60c93c3602043c728f5db3b97bdb548467f7bddea"
-"checksum utf8-ranges 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "9d50aa7650df78abf942826607c62468ce18d9019673d4a2ebe1865dbb96ffde"
 "checksum uuid 0.7.4 (registry+https://github.com/rust-lang/crates.io-index)" = "90dbc611eb48397705a6b0f6e917da23ae517e4d127123d2cf7674206627d32a"
 "checksum vec_map 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)" = "05c78687fb1a80548ae3250346c3db86a80a7cdd77bda190189f2d0a0987c81a"
 "checksum version_check 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "914b1a6776c4c929a602fafd8bc742e06365d4bcbe48c30f9cca5824f70dc9dd"
diff --git a/crates/ra_hir/Cargo.toml b/crates/ra_hir/Cargo.toml
index 285b3c63a..1a2f1b47c 100644
--- a/crates/ra_hir/Cargo.toml
+++ b/crates/ra_hir/Cargo.toml
@@ -27,4 +27,4 @@ chalk-ir = { git = "https://github.com/rust-lang/chalk.git" }
 lalrpop-intern = "0.15.1"
 
 [dev-dependencies]
-insta = "0.9.0"
+insta = "0.10.0"
diff --git a/crates/ra_hir/src/source_binder.rs b/crates/ra_hir/src/source_binder.rs
index c2c6921cb..e86716d74 100644
--- a/crates/ra_hir/src/source_binder.rs
+++ b/crates/ra_hir/src/source_binder.rs
@@ -18,14 +18,18 @@ use ra_syntax::{
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use crate::{
-    expr,
     expr::{
+        self,
         scope::{ExprScopes, ScopeId},
         BodySourceMap,
     },
     ids::LocationCtx,
+    name,
+    path::{PathKind, PathSegment},
+    ty::method_resolution::implements_trait,
     AsName, AstId, Const, Crate, DefWithBody, Either, Enum, Function, HirDatabase, HirFileId,
-    MacroDef, Module, Name, Path, PerNs, Resolver, Static, Struct, Trait, Ty,
+    MacroDef, Module, ModuleDef, Name, Path, PerNs, Resolution, Resolver, Static, Struct, Trait,
+    Ty,
 };
 
 /// Locates the module by `FileId`. Picks topmost module in the file.
@@ -409,6 +413,33 @@ impl SourceAnalyzer {
         crate::ty::autoderef(db, &self.resolver, canonical).map(|canonical| canonical.value)
     }
 
+    /// Checks that particular type `ty` implements `std::future::Future`.
+    /// This function is used in `.await` syntax completion.
+    pub fn impls_future(&self, db: &impl HirDatabase, ty: Ty) -> bool {
+        let std_future_path = Path {
+            kind: PathKind::Abs,
+            segments: vec![
+                PathSegment { name: name::STD, args_and_bindings: None },
+                PathSegment { name: name::FUTURE_MOD, args_and_bindings: None },
+                PathSegment { name: name::FUTURE_TYPE, args_and_bindings: None },
+            ],
+        };
+
+        let std_future_trait =
+            match self.resolver.resolve_path_segments(db, &std_future_path).into_fully_resolved() {
+                PerNs { types: Some(Resolution::Def(ModuleDef::Trait(trait_))), .. } => trait_,
+                _ => return false,
+            };
+
+        let krate = match self.resolver.krate() {
+            Some(krate) => krate,
+            _ => return false,
+        };
+
+        let canonical_ty = crate::ty::Canonical { value: ty, num_vars: 0 };
+        implements_trait(&canonical_ty, db, &self.resolver, krate, std_future_trait)
+    }
+
     #[cfg(test)]
     pub(crate) fn body_source_map(&self) -> Arc<BodySourceMap> {
         self.body_source_map.clone().unwrap()
diff --git a/crates/ra_hir/src/ty/method_resolution.rs b/crates/ra_hir/src/ty/method_resolution.rs
index d421bf9ef..88d012a74 100644
--- a/crates/ra_hir/src/ty/method_resolution.rs
+++ b/crates/ra_hir/src/ty/method_resolution.rs
@@ -255,6 +255,20 @@ fn iterate_inherent_methods<T>(
     None
 }
 
+pub(crate) fn implements_trait(
+    ty: &Canonical<Ty>,
+    db: &impl HirDatabase,
+    resolver: &Resolver,
+    krate: Crate,
+    trait_: Trait,
+) -> bool {
+    let env = lower::trait_env(db, resolver);
+    let goal = generic_implements_goal(db, env.clone(), trait_, ty.clone());
+    let solution = db.trait_solve(krate, goal);
+
+    solution.is_some()
+}
+
 impl Ty {
     // This would be nicer if it just returned an iterator, but that runs into
     // lifetime problems, because we need to borrow temp `CrateImplBlocks`.
diff --git a/crates/ra_ide_api/Cargo.toml b/crates/ra_ide_api/Cargo.toml
index dd11ec0f6..a7dc0b63a 100644
--- a/crates/ra_ide_api/Cargo.toml
+++ b/crates/ra_ide_api/Cargo.toml
@@ -27,7 +27,7 @@ test_utils = { path = "../test_utils" }
 ra_assists = { path = "../ra_assists" }
 
 [dev-dependencies]
-insta = "0.9.0"
+insta = "0.10.0"
 
 [dev-dependencies.proptest]
 version = "0.9.0"
diff --git a/crates/ra_ide_api/src/completion/complete_dot.rs b/crates/ra_ide_api/src/completion/complete_dot.rs
index 536ba36df..d43ff2eec 100644
--- a/crates/ra_ide_api/src/completion/complete_dot.rs
+++ b/crates/ra_ide_api/src/completion/complete_dot.rs
@@ -1,19 +1,36 @@
 use hir::{AdtDef, Ty, TypeCtor};
 
-use crate::completion::{CompletionContext, Completions};
+use crate::completion::completion_item::CompletionKind;
+use crate::{
+    completion::{completion_context::CompletionContext, completion_item::Completions},
+    CompletionItem,
+};
 use rustc_hash::FxHashSet;
 
-/// Complete dot accesses, i.e. fields or methods (currently only fields).
+/// Complete dot accesses, i.e. fields or methods (and .await syntax).
 pub(super) fn complete_dot(acc: &mut Completions, ctx: &CompletionContext) {
-    let receiver_ty =
-        match ctx.dot_receiver.as_ref().and_then(|it| ctx.analyzer.type_of(ctx.db, it)) {
-            Some(it) => it,
-            None => return,
-        };
+    let dot_receiver = match &ctx.dot_receiver {
+        Some(expr) => expr,
+        _ => return,
+    };
+
+    let receiver_ty = match ctx.analyzer.type_of(ctx.db, &dot_receiver) {
+        Some(ty) => ty,
+        _ => return,
+    };
+
     if !ctx.is_call {
         complete_fields(acc, ctx, receiver_ty.clone());
     }
-    complete_methods(acc, ctx, receiver_ty);
+    complete_methods(acc, ctx, receiver_ty.clone());
+
+    // Suggest .await syntax for types that implement Future trait
+    if ctx.analyzer.impls_future(ctx.db, receiver_ty) {
+        CompletionItem::new(CompletionKind::Keyword, ctx.source_range(), "await")
+            .detail("expr.await")
+            .insert_text("await")
+            .add_to(acc);
+    }
 }
 
 fn complete_fields(acc: &mut Completions, ctx: &CompletionContext, receiver: Ty) {
@@ -406,4 +423,36 @@ mod tests {
         "###
         );
     }
+
+    #[test]
+    fn test_completion_await_impls_future() {
+        assert_debug_snapshot_matches!(
+        do_completion(
+            r###"
+            //- /main.rs
+            use std::future::*;
+            struct A {}
+            impl Future for A {}
+            fn foo(a: A) {
+                a.<|>
+            }
+
+            //- /std/lib.rs
+            pub mod future {
+                pub trait Future {}
+            }
+            "###, CompletionKind::Keyword),
+        @r###"
+       ⋮[
+       ⋮    CompletionItem {
+       ⋮        label: "await",
+       ⋮        source_range: [74; 74),
+       ⋮        delete: [74; 74),
+       ⋮        insert: "await",
+       ⋮        detail: "expr.await",
+       ⋮    },
+       ⋮]
+        "###
+        )
+    }
 }
diff --git a/crates/ra_syntax/Cargo.toml b/crates/ra_syntax/Cargo.toml
index bc1c88070..5f8585878 100644
--- a/crates/ra_syntax/Cargo.toml
+++ b/crates/ra_syntax/Cargo.toml
@@ -8,7 +8,6 @@ description = "Comment and whitespace preserving parser for the Rust langauge"
 repository = "https://github.com/rust-analyzer/rust-analyzer"
 
 [dependencies]
-unicode-xid = "0.1.0"
 itertools = "0.8.0"
 rowan = "0.6.1"
 ra_rustc_lexer = { version = "0.1.0-pre.2" }