Rust type alias. Type aliases are created using the type keyword.
Rust type alias In the following snippet, two # [cxx::bridge] invocations in May 3, 2023 · It's a general fact about type aliases. I removed the type annotation on xSquared, which is unnecessary. But the alias needs to be defined inside the struct. Examples type does not create a new type: The Alias variant wraps an AliasTy and is used to represent some form of type alias. Jun 9, 2021 · I try to define alias for BlockMode, so I can use it as function argument, but it error out, pls advise fn encrypt (cipher: impl BlockMode<C: BlockCipher + BlockEncrypt + BlockDecrypt, P: Padding>) { // It seems like the main issue here is which of the uses of the type alias is being used to define the type. This is useful when you have a long type and want to give it something easier. Here are two examples of type aliases. For example rust::String, rust::Vec may alternatively be written rust::string, rust::vec etc. And the first thing I found is that Rust really cares about origin of types (Protected designation of Mar 18, 2019 · A type alias (type Foo = Bar) does not create a new type. Key to this are the & (shared/“immutable”) and &mut (unique/mutable) reference types. Define an alias for an existing type. Can you given an example of a way that supporting enum variant aliases would break something because I can't see any. Aliasing is useful for the optimization of data. In Aliasing, only one data can be mutably borrowed at a time. Usually a use declaration is used to shorten the path required to refer to a module item. Associated types: this occurs within traits and trait impl blocks. type aliases only the type, not the constructor. I would like to provide an alias for this, not only to avoid typing but also to avoid errors. When speaking of "newtype", we usually mean the following: struct MyStruct<T> { foo: T } struct MyStructA(MyStruct<u32>); struct MyStructB(MyStruct<u64>); i. Every value has a single, specific type, but may implement several different traits, or be compatible with several different type constraints. For example, we can create the alias Kilometers to i32 like so: Impl trait initiative Impl trait in type aliases Rust has a concept of type aliases, which let you declare one type name as an alias for another: Is there any way to create a type alias for multiple traits? Asked 11 years, 1 month ago Modified 3 years, 11 months ago Viewed 18k times Oct 26, 2021 · When you create List type (or any other type), it’s idiomatic to write impl for that type. Other kinds of types are enums, scalar primitive types, and compound primitive types. Rust's 'orphan rules' require your crate to have defined one or both Mar 27, 2023 · 1 use serde_json:: {Result, Value}; You import Result from serde_json here which overrides your default prelude of std::result::Result. For example, the following defines Hack features type aliasing using the newtype keyword. For example, the following defines the type Point as a synonym for the type (u8, u8), the type of pairs of unsigned 8 bit integers: Nov 7, 2025 · While usual Rust style is to import types directly, aliases of Result often are not, to make it easier to distinguish between them. This also works with more complex types and structur Type aliases If you use a type alias, you can refer to each enum variant via its alias. See examples of impl Trait in function arguments, type aliases, and code within modules. Feb 14, 2025 · Also, usage of a type only in trait bounds isn't considered "being used". Here's the final code: Mar 20, 2017 · So I refactored it into a type alias: pub type Some = FnMut(u8, u17, &str). While type aliases and associated types both use the type keyword, they're not quite the same thing. This might be useful if the enum's name is too long or too generic, and you want to rename it. Use parentheses around a type to avoid ambiguity. In #110237 this was split off to impl_trait_in_assoc_type. Type aliases are very easy. Oct 3, 2020 · Second, in Rust community, "newtype pattern" is not the thing you've described. E. The type alias helps in two ways: it makes code easier to write and it gives us a consistent interface across all of std::io. May 24, 2015 · Is it possible to create a trait alias with specified associated types? I'm using a method from similar question Type alias for multiple traits trait Trait { type Item; } fn print<T>(va Jun 8, 2022 · In this case, in the future a feature like type_alias_impl_trait might be useful for you, or right now you could use a wrapper struct with a cfg'd field instead of a type alias, so the type is actually the same, regardless of target_arch. I can see how "color" is a special case, but is Point necessarily different? Nov 8, 2015 · Is there a way to make the code below work? That is, export an enum under a type alias, and allow access to the variants under the new name? enum One { A, B, C } type Two = One; fn main() { // Jul 27, 2017 · The lifetime is declared after the name of the type alias, and the lifetime of &str is specified to be 'a. In other words, because Rust is strongly typed, you’d expect a comparison between two different types to fail: Mark the given typedef as a regular Rust type alias. e. rs:7:5 | 7 | Bar | ^^^ | = note: can't use a type alias as a constructor As for Self working even though it looks like an alias, well, it is a special case. Therefore, trying to implement Debug for MyFn is exactly the same as trying to implement it for Box<Fn(usize) -> bool> - which is not allowed, since your crate doesn't own the type or the trait. In other words, because Rust is strongly typed, you’d expect a comparison between two different types to fail: Jun 17, 2016 · Is it possible to create a type alias that contains trait requirements on a function pointer? Obviously the compiler is telling me no for types, but didn't know if there was another option for functions that I wasn't thinking of. That doesn't seem to be the case, as creating a manual type alias and using that instead doesn't work. Currently, the right hand side is a bound – a single trait, a combination with + traits and lifetimes. 48. type_alias_impl_trait in argument position. Unfortunately, this isn't possible currently and from a brief glance at the tracking issue, I don't think that it will land soon. However, I want to use the ones that already exist under glib-sys. Motivation RFC 2071 described a method to define opaque types satisfying Rust by Example (RBE) is a collection of runnable examples that illustrate various Rust concepts and standard libraries. It is also good when you want to give a type a better name that is easy to remember. For this we use the type keyword. Isn't all information needed in the type which generated the opaque type (Connect)? And broader question is, how do I make low-level (poll) based approach Easy Rust Type aliases A type alias means "giving a new name to another type". Sep 25, 2020 · When defining a type alias containing a reference, the compiler wants us to make the lifetime explicit, probably to prevent someone using this type alias from forgetting that there is a reference hidden inside. Aug 12, 2022 · This is a follow-up to this question: Use existing bindings from a *-sys crate with bindgen I have a *-sys crate that depends on the system library glib. Motivation First motivation: impl A type alias defines a new name for an existing type. Feb 8, 2023 · I would like to use a type alias for some occurences of [u8] and Vec<u8> in my code (mostly for documentation purposes / code clarity). It is if it ends up being constrained, which is the case in the OP -- ActingFn is in the alias, and Fut is the return type which is equivalent to an associated type equality bound with ActingFn as the implementer. Jun 24, 2019 · Creating a type alias does not create an entirely new type, it just allows you to refer to the existing type via a different name. Currently, my *-sys crate re-generates those bindings. Jun 8, 2022 · In this case, in the future a feature like type_alias_impl_trait might be useful for you, or right now you could use a wrapper struct with a cfg'd field instead of a type alias, so the type is actually the same, regardless of target_arch. They are used to represent a number of related Rust concepts, include actual type aliases, associated types, and opaque types -- you can read about them in the aliases chapter. Jul 8, 2017 · However, the type alias is actually used -- if I remove it, the code stops compiling because the impl block references the alias. type Meters = u32; type Kilograms = u32; let m: Meters = 3; let k: Kilograms = 3; assert_eq!(m, k); The Rust Reference Type aliases Syntax TypeAlias : type IDENTIFIER Generics? WhereClause? = Type ; A type alias defines a new name for an existing type. Learn how to use impl Trait to declare a type alias for any type that implements a trait, without specifying the exact type name. To keep code more readable, we can use type aliases. A type alias lets you refer to the type as another name. Rust by Example (RBE) is a collection of runnable examples that illustrate various Rust concepts and standard libraries. Alternatively, you could namespace it via modules this way: pub mod foo { pub struct Foo; pub type Result = String Oct 31, 2023 · The docs say: The # [aliases ()] is just syntactic sugar and will create Rust type aliases behind the scenes which then can be later referenced anywhere in code. Maybe there needs to be a way to make that explicit. another way for me to implement The normal solution is to create a brand new type. With the type keyword, we alias an identifier to an actual Rust type. This is the default behavior, meaning that this method only comes into effect if a style different from AliasVariation::TypeAlias was passed to the Builder::default_alias_style method. Creating Type Synonyms with Type Aliases Rust provides the ability to declare a type alias to give an existing type another name. In fact, real structure expressions (A { foo: bar }) do work with type-aliases - these aren't just calls to a constructor. Originally this feature included type aliases as an associated type of a trait. These allow aliases to be created for one or more traits (currently just a single regular trait plus any number of auto-traits), and used wherever traits would normally be used as either bounds or trait objects. Moreover, there is a direct analogue with use to pub type, it's pub use: // will be available to other modules pub use hyper::status::StatusCode as Error; However, there are differences in more complex cases. The problem to solve is the following: we have two bridges, one exporting the Rust type, the other declaring functions, which need to work with this type. This let me remove the type alias completely. g. The new type pattern serves as a good solution to sidestepping orphan rules, but it Jun 28, 2019 · A struct is a type-- "type" is the more general category; struct is one kind of type. Currently, The trait_alias feature adds support for trait aliases. [6] Functionally, this creates a new, distinct type that is incompatible with its underlying type (int). For example, the + operator for type boundaries within a reference type is unclear where the boundary applies, so the use of parentheses is required. The standard library defines more structs and enums such as String and Option<T>, and you can define your Mar 1, 2023 · In #1181, I published a tentative implementation for Rust type aliases. Instead, use the existing type alias functionality: Oct 2, 2016 · Suppose I use a crate, that defines a type (struct or enum) Foo, is there a difference between: extern crate foo; pub type Bar = foo::Foo; and extern crate foo; pub use foo::Foo as Bar; ? I'm aware that type and use work differently for modules and generic types, but are they the same for simple types? If not, in which one is preferred and why? Also, why are there two very similar language Dec 22, 2014 · The compiler won't let us use a type alias in a type parameter constraint; we need to spell out the trait fully. This means we can use the simple and short alias in place of the more complex real type This doesn't usually cause problems with type inference, as there will only be one type F that works for a given C (at least in this example), but it does make certain uses noisier, since to specify the type F you have to also put a placeholder for C and vice versa. Type Km is a synonym for i32. May 13, 2016 · I have a generic struct and its implementations uses many times the following callable signature Fn(&SomeType, &SomeOtherType, &T) -> MyResult as argument type in different functions (T is the generic Type). For example, the following defines Dec 17, 2021 · For the sake of readability, I can't just use single letters like I have in the examples above, so I would really want to create a generic type alias in the struct like so: Jan 3, 2025 · Type Aliases in Impl Blocks Another powerful feature Rust provides is type aliases, which are convenient ways to create shorter or more meaningful names for existing types. Jan 22, 2017 · Yes I'm trying to create aliases. A type alias defines a new name for an existing type in the type namespace of the module or block where it is located. This is useful for serializing fields as camelCase or serializing fields with names that are reserved Rust keywords. I found that bindings to items from glib already exist in the glib-sys crate. Either remove the import or alias it, for example: use serde_json::Result as SerdeJsonResult; A place for all things related to the Rust programming language—an open-source systems language that emphasizes performance, reliability, and productivity. impl Trait provides ways to specify unnamed but concrete types that implement a specific trait. Oct 5, 2021 · tl;dr in Rust, is there a "strong" type alias (or typing mechanism) such that the rustc compiler will reject (emit an error) for mix-ups that may be the same underlying type? Problem Curr Type Aliases Create Type Synonyms Alongside the newtype pattern, Rust provides the ability to declare a type alias to give an existing type another name. Examples Field attributes #[serde(rename = "name")] Serialize and deserialize this field with the given name instead of its Rust name. A place for all things related to the Rust programming language—an open-source systems language that emphasizes performance, reliability, and productivity. A type alias defines a new name for an existing type in the type namespace of the module or block where it is located. Rust already has type aliases with no problems. Unlike type aliases, a struct alias is an owned type, so foreign traits can be implemented on it. Good practice and all that. Oct 16, 2018 · You’re talking about an associated type here, not a type alias - just wanted to make sure you have the right terminology in place in case you want to do some additional research. . The Rust Reference. Where clauses before the equals sign on a type alias in a trait impl (like type TypeAlias<T> where T: Foo = Bar<T>) are deprecated. Associated types are Type aliases Syntax TypeAlias : type IDENTIFIER GenericParams? ( : TypeParamBounds )? WhereClause? ( = Type )? ; A type alias defines a new name for an existing type. Where clauses before the equals sign on a type alias in a trait impl (like type Type Alias <T> where T: Foo = Bar<T>) are deprecated. I guess I have to define two separate alias like the following? pub type Content = [u8]; pub type OwnedContent = <Content as ToOwned>::Owned; pub fn foo(_content: &Content) { todo!() } pub fn bar() -> OwnedContent { todo!() } (Playground) Or is there any more Jan 11, 2017 · How can I define an associated const or type alias in Rust? Asked 8 years, 10 months ago Modified 8 years, 10 months ago Viewed 2k times Nov 9, 2020 · I'm trying to give an alias to a function so I don't have to write its signature whenever I implement this trait: type PhySend = Fn (); trait MyTrait { fn set_phy_send<F: PhySend> (callback The rust namespace additionally provides lowercase type aliases of all the types mentioned in the table, for use in codebases preferring that style. That would mean that, in your case, you wouldn't be able to use this with multiple different closures, since every closure has its own unique type. Allows specifying independent names for serialization vs deserialization: #[serde(rename(serialize = "ser_name"))] #[serde(rename(deserialize = "de_name Aug 16, 2022 · Any idea how I can fix the type alias to add the trait bound? (I thought the where std::io::Cursor<T>: std::io::Write would do the trick, but apparently it doesn't. Say I type alias a basic type, how do I get an error when the aliased type no longer match, but the underlying basic type does? Take this code… Jul 8, 2017 · However, the type alias is actually used -- if I remove it, the code stops compiling because the impl block references the alias. By wrapping `phys_addr_t` in a transparent Rust newtype, we avoid accidentally mixing physical addresses with virtual addresses or other integer-like values. This means the type alias is basically useless. This trait serves the following two related purposes. A function type in Rust is the type that was generated. Mar 11, 2024 · An answer I received on Stack Overflow suggested the use of the experimental trait_alias (Rust Playground) But I was hoping that this might exist already and I just didnt understand how to do it properly? Feb 21, 2023 · Rustではtypeキーワードで型エイリアスを定義し、既存の型に別名を付けられる。 type - Rust Type aliases - The Rust Reference エイリアス - Rust By Example 日本語版目次 typeで型エイリアスを定義 typeの型エイリアスで出来るこ A use declaration creates one or more local name bindings synonymous with some other path. The syntax is type Name = ExistingType;. When create a variable , give it type annotation of Km , its type is i32. A use declaration is also sometimes called an import, or, if it is public, a re-export. Rust’s safety guarantees hinge around control how data is aliased/can be manipulated while aliased. This doesn't work either: struct Foo; type Bar = Foo; fn test() -> Bar { Bar } error[E0423]: expected value, found type alias `Bar` --> src/lib. A type for which the layout is determined by its C++ definition. Is there a way to do this? Jul 10, 2015 · The struct constructor is pretty much an ordinary constant/function (with type A if the struct is nullary, or type fn(Foo,Bar)->A if the struct contains fields). A type alias, when used as an associated type in a trait impl, must include a Type specification and may not include TypeParamBounds. Lifetimes on types can be elided in functions sometimes, which is why you can write &str. Aug 31, 2016 · Feature Name: Trait alias Start Date: 2016-08-31 RFC PR: rust-lang/rfcs#1733 Rust Issue: rust-lang/rust#41517 Summary Traits can be aliased with the trait TraitAlias = …; construct. Alternatively, you could namespace it via modules this way: pub mod foo { pub struct Foo; pub type Result = String In some situations the combination of types may be ambiguous. Type aliases Syntax TypeAlias : type IDENTIFIER GenericParams? ( : TypeParamBounds )? WhereClause? ( = Type )? ; A type alias defines a new name for an existing type. Jan 2, 2010 · What is type alias in Rust? In Rust, a type alias allows you to create a new name for an existing type. If you can create an minimal reproducible example and specify both Rust version that show the regression, summit an issue, I didn't find any one about your case currently open. Nov 15, 2021 · Also, an associated type can be named in terms of the Self -type (and the other type parameters), so that you save the need for additional type parameters in generic functions working with the trait, and more importantly also structs containing the type. Why? Is there some edge case that makes this difficult? This seems to violate the principle of least surprise. Every value has a single, specific type, but may implement several different traits, and may be compatible with several different type constraints. A guide to developing the Rust compiler (rustc)Opaque types (type alias impl Trait) Opaque types are syntax to declare an opaque type alias that only exposes a specific set of traits as their interface; the concrete type in the background is inferred from a certain set of use sites of the opaque type. This is stricter than a simple alias, which is generally transparent and interchangeable with the original type. Jun 17, 2024 · Rust has a few useful features for making backwards-compatible API changes — type aliases, pub use, default method implementations in traits, and simply ability for inherent methods to forward calls to another method, and all of that can be shoved under #[doc(hidden)]. You could achieve it via associated types as mentioned. Apr 4, 2015 · Rust type keyword The type keyword in rust has a different meaning in the 2 places it can be used: Type alias: Just another name for the same type. Because we make Feb 15, 2018 · It’s reasonable to expect that a type alias can fully replace the original type specification, and so the lack of working support for aliased enum variants represents an ergonomic gap in the language/type system. | ^^^ missing associated type `Output` value Is there any way to create an alias of a specific FnMut which I can use instead of FnMut(&[f32]) -> f32? In some situations the combination of types may be ambiguous. Grammar rules that require this disambiguation use the TypeNoBounds rule instead of Mar 16, 2022 · The most straightforward way would be an inherent associated type, used like this: playground. Result is generally assumed to be std::result::Result, and so users of this alias will generally use io::Result instead of shadowing the prelude ’s import of std::result::Result. newtype is simply a single-valued tuple struct. struct NewStruct = ForeignStruct; Rationale Their main purpose is to make the new type pattern more ergonomic and involve less boilerplate. If a type Item has an associated type Assoc from a trait Trait, then <Item as Trait>::Assoc is a type that is an alias of the type specified in the associated type definition We use type keyword with name Km to create a type alias to the i32 type. So it works with lazy_type_alias or as a struct on stable. These declarations may appear in modules and blocks, usually at the top. Bound on generic parameter in type alias I encountered this warning for the first time, and would like both to understand its motivation and potentially discuss improving the warning messages. This is expressed by using impl Trait within type aliases, for example: In some situations the combination of types may be ambiguous. This can be useful in exposing an interface from a dependency to library users while “hiding” the exact implementation details. Note, however, that this is an alias, not a new type entirely. 4 days ago · Convert the use of `phys_addr_t` in the Rust kernel bindings into a dedicated `PhysAddr` newtype to provide stronger type safety around physical addresses. Then, using this type alias requires the <'> notation. This, however, would probably not help, since MyStructA and MyStructB will have totally independent A type alias defines a new name for an existing type in the type namespace of the module or block where it is located. If you want to create an alias to a tuple, you can use the type keyword to create an alias. Benefits of Type Aliases Improved Readability: By giving a meaningful name to a type, you can make your code more understandable Jun 28, 2016 · In case of simple types, like in your example, there doesn't seem to be any semantic difference. Associated types are used to define a trait that uses some type (s) without needing to know exactly what those types are until the trait is implemented. Say I type alias a basic type, how do I get an error when the aliased type no longer match, but the underlying basic type does? Take this code… Jan 4, 2023 · I am trying to use #![feature(type_alias_impl_trait)] and I am getting cycle detected when computing type of discovery::ConnFuture::{opaque#0}` I do not understand why does Rust need to analyze type of where alias is used (Discovery). stuff: String, thing: Alias, } In this example, the concrete type referred to by Alias is guaranteed to be the same wherever Alias occurs. It seems to take the name, but then falls back to the same problem. In Rust, you are not allowed to implement inherent methods for a type that comes from another crate. In fact, it goes by the name Aug 3, 2018 · Feature Name: type_alias_impl_trait Start Date: 2018-08-03 RFC PR: rust-lang/rfcs#2515 Rust Issue: rust-lang/rust#63063 Summary Allow type aliases and associated types to use impl Trait, replacing the prototype existential type as a way to declare type aliases and associated types for opaque, uniquely inferred types. Sep 14, 2019 · This is slightly different though. All it does is create a different name that refers to the existing type. They help you write code that's easier to understand, harder to misuse, and safer overall. Type aliases are created using the type keyword. Contribute to rust-lang/reference development by creating an account on GitHub. May 17, 2023 · If you need stricter type checking, the usual way is a light wrapper: struct Color(Vec3) which has impl Deref<Vec3>. For example, you can define generic type aliases or aliases for specialized generic types Mar 31, 2025 · Define an alias for an existing type. Type aliases can be defined inside impl blocks, providing an abstraction layer and improving code clarity when working with complex type names, especially in generics. Jun 3, 2025 · Enter type aliases and newtypes: two powerful tools for giving raw types clearer meaning and enforcing type safety. It can appear in two sorts of places: argument position (where it can act as an anonymous type parameter to functions), and return position (where it can act as an abstract return type). Dec 3, 2018 · Rust follow semver, breaking change would imply that Rust up the major version so if you really found a regression it's a bug. Safely unifying occurrences of the same extern type ExternType makes it possible for CXX to safely share a consistent Rust type across multiple # [cxx::bridge] invocations that refer to a common extern C++ type. Field attributes #[serde(rename = "name")] Serialize and deserialize this field with the given name instead of its Rust name. Grammar rules that require this disambiguation use the TypeNoBounds rule instead of Type. Both the newtype idiom and type alias have their uses and you should learn how to use each. In some situations the combination of types may be ambiguous. 深入 Rust 类型 弱弱地、不负责任地说，Rust 的学习难度之恶名，可能有一半来源于 Rust 的类型系统，而其中一半的一半则来自于本章节的内容。在本章，我们将重点学习如何创建自定义类型，以及了解何为动态大小的类型。 newtype 何为 newtype？简单来说，就是使用 元组结构体 的方式将已有的类型 Sep 25, 2024 · It doesn't make sense to translate a C typedef into a Rust fn, since the typedef in C represents a function type, not a function. Type parameters and lifetimes can be added to the trait alias if needed. Hence, there should be no warning. This allows the API to clearly express intent at call sites and makes misuse Apr 3, 2015 · How exactly does type aliasing work in Rust? I've been examining breakage in some old Rust code I didn't write and noticed that Thunk::new() causes this error: error: type `Box<alloc::box We would like to show you a description here but the site won’t allow us. The Alias variant wraps an AliasTy and is used to represent some form of type alias. Instead, use the existing type alias functionality: Learn about advanced Rust programming concepts like newtypes, type aliases, the ! type, and dynamically sized types in this comprehensive tutorial. Type aliases in Rust allow you to create alternative names for existing types, making your code more readable, maintainable, and expressive. The core Rust language defines the primitive types and the mechanism by which new structs and enums can be created. This can make your code more readable and easier to manage, especially when dealing with complex types. For example, we can create the alias Kilometers to i32 like so: Learn about advanced Rust programming concepts like newtypes, type aliases, the ! type, and dynamically sized types in this comprehensive tutorial. Because it’s an alias, it’s just another Result<T, E>, which means we can use any methods that work on Result<T, E> with it, as well as special syntax like the ? operator. Type aliases If you use a type alias, you can refer to each enum variant via its alias. Type aliases are declared with the keyword type. Nov 24, 2020 · No, it is not possible to declare a type alias inside a trait as of Rust 1. I'm pretty confident that you have not always been able Learn about enums, a powerful feature in Rust that allows creating custom data types with multiple variants, and how to use type aliases to make your code more concise and readable. Dec 18, 2017 · C offers the keyword typedef which lets you alias another type: typedef unsigned int uint; This basically makes uint an alias for unsigned int. Type Often in Rust programs, types can become complex—this is particularly problematic in multithreaded programs with Mutex and Arc. To do this, I blocklisted glib's types in Oct 28, 2020 · Your suggestion would work if I only needed to call alias_to_sum from other Rust code, but in the motivating problem I need a symbol with that name to be present in final binary to resolve symbols in a shared object. May 24, 2015 · Is it possible to create a trait alias with specified associated types? I'm using a method from similar question Type alias for multiple traits trait Trait { type Item; } fn print<T>(va Jul 7, 2022 · A struct alias would be a way to construct a new type from a previous one. When we alias with type X = impl Trait, the compiler will ensure that every usage of X is actually the same concrete type. Sep 15, 2022 · Rust is statically typed and there is a concept of Alias which states that data can be borrowed immutably but during borrowing, the original data cannot be borrowed mutably. Usually you use them when you have a very long type and don't want to write it every time. But rustc doesn't like it, moaning about type aliases cannot be used for traits. In this guide, we'll explore how type aliases work in Rust, when to use them, and how they can improve your code quality. ooclu ilyeh vhks orfvr tlj sgejrq uvpm vbjwu zlfavpz jbv nop akvntt nmdczwk icc jjjqv