is_array
Applicability
Product |
Supported |
|---|---|
Atlas 350 Accelerator Card |
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x |
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Function Usage
Checks whether a type is the array type during program compilation. This API can be used for type checking and conditional processing during compilation.
Prototype
1 2 | template <typename Tp> struct is_array; |
Parameters
Parameter |
Description |
|---|---|
Tp |
Types to be checked, including basic types (such as int and float), composite types (such as pointer and reference), user-defined types (such as class and struct), and the array type |
Restrictions
None
Returns
The static constant member value of is_array is used to obtain the returned Boolean value. The values of is_array<Tp>::value are as follows:
- true: Tp is of the array type.
- false: Tp is not of the array type.
Examples
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 | // Custom test type struct MyStruct{}; using FuncType = int(int); // Legitimate array types AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<int[5]>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<char[]>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<double[2][3]>::value); // Array types limited by CV AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<const int[10]>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<volatile char[3]>::value); // non-array types AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<int*>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<int>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<double>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<MyStruct>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<FuncType>::value); AscendC::printf("AscendC::Std::is_array::value:%d\n", AscendC::Std::is_array<void>::value); |
// Execution result AscendC::Std::is_array::value:1 AscendC::Std::is_array::value:1 AscendC::Std::is_array::value:1 AscendC::Std::is_array::value:1 AscendC::Std::is_array::value:1 AscendC::Std::is_array::value:0 AscendC::Std::is_array::value:0 AscendC::Std::is_array::value:0 AscendC::Std::is_array::value:0 AscendC::Std::is_array::value:0 AscendC::Std::is_array::value:0