std::is

std::is_trivially_destructible来判断 一个 内置类型或structure/class/union类型 是否为 “容易销毁的(trivially destructible)”，从字面意思也可以看出，主要是check这个类型的 析构函数。官网给出如下解释：

A trivially destructible class is a class (defined with class, struct or union) that:

uses the implicitly defined destructor.the destructor is not virtual.its base class and non-static data members (if any) are themselves also trivially destructible types.

也就是说，如果一个类定义了非默认的析构函数，比如类的构造函数中有new，那么需要自写析构来delete，那么std::is_trivially_destructible::value将返回false。

如果一个类中的 非静态成员变量 是 not rivially destructible types，那么 这个类 也将是not rivially destructible types，std::is_trivially_destructible::value将返回false。

在SystemC中，对于sc_bv 类型，由于其基类sc_bv_base有自定义析构函数，所以std::is_trivially_destructible>::value 返回false。

    virtual ~sc_bv_base()
    { delete [] m_data; }

参考：

is_trivially_destructible - C++ Reference

C++ std::is_trivially_destructible用法及代码示例 - 纯净天空

STL in C++11 (Allocator 2) - 简书

// execute:
//     g++ -g -Wall -lsystemc -m64 -pthread main.cpp
//         -L/$(your systemc path)/lib-linux64
//         -I/$(your systemc path)/include  -I/$(your systemc path)/src/tlm_utils -o sim

#include 

// C++ program to illustrate
// std::is_trivially_destructible
#include 
#include 
using namespace std;

struct Y
{
  Y(int, int){};
};

struct X
{
  // Destructor
  ~X() noexcept(false)
  {
  }
};

struct Z
{
  ~Z() = default;
};

class A
{
  virtual void fn() {}
};

class MyBvClass
{
  sc_dt::sc_bv<2> m_test_mem;
};

int sc_main(int argc, char **argv)
{
  cout << boolalpha;
  cout << "int:"
       << std::is_trivially_destructible::value
       << endl;
  cout << "struct X:"
       << std::is_trivially_destructible::value
       << endl;
  cout << "struct Y:"
       << std::is_trivially_destructible::value
       << endl;
  cout << "struct Z:"
       << std::is_trivially_destructible::value
       << endl;
  cout << "class A:"
       << std::is_trivially_destructible::value
       << endl;
  cout << "class MyBvClass:"
       << std::is_trivially_destructible::value
       << endl;

  sc_core::sc_start();
  return 0;
}