// 字面值类类型 class Debug { public: constexpr Debug(bool b = true): hw(b), io(b), other(b) {} constexpr Debug(bool h, bool i, bool o): hw(h), io(i), other(o) {} constexpr bool any() const { return hw || io || other;
在提案 constexpr member functions and implicit const 中指出:如果一个成员函数是 constexpr 的,它不一定一定要是 const 的。随着 constexpr 计算中的可变性变得越来越重要,这一点变得更加突出。但即使在此之前,它也妨碍了在 constexpr 和非 constexpr 代码中使用相同的函数: ...
And we can haveconstandconstexprmember functions: structPoint{intx{0};inty{0};constexprintdistX(constPoint&other)const{returnabs(x-other.x);}constexprvoidmul(intv){x*=v;y*=v;}}; In the above scenario,constexprmeans that the function can be evaluated for constant expressions, butconsti...
Function: return constexpr result if called with constexpr args constexpr Objects must initialized with value known during compilation constexprstd::size_t arraySize// error! no initializerintsz// non-constexpr variable...constexprautoarraySize1=sz// error! sz's value not know// at compilatio...
/* We can see a FIELD_DECL in a pointer-to-member expression. */ case FIELD_DECL: case PARM_DECL: case USING_DECL: return true; case AGGR_INIT_EXPR: case CALL_EXPR: /* -- an invocation of a function other than a constexpr function ...
/* We can see a FIELD_DECL in a pointer-to-member expression. */ case FIELD_DECL: case PARM_DECL: case USING_DECL: return true; case AGGR_INIT_EXPR: case CALL_EXPR: /* -- an invocation of a function other than a constexpr function ...
const struct Foo *f = new Foo;f->dataX = 100; //compile errorconstchar* p ="abc";p[1] ='x'; //compile errorf->nonconst_member_function(); ///compile error (后面再讲) 1. 2. 3. 4. 5. 6. [3] 修饰指针 T* const p:表示指针只能在初始化时设置指向,之后便不能修改指向。
Aconstexprnon-staticmember function isn't required to be implicitlyconst. C++ constexprfloatexp(floatx,intn){returnn ==0?1: n %2==0?exp(x * x, n /2) :exp(x * x, (n -1) /2) * x; } Tip In the Visual Studio debugger, when debugging a non-optimised Debug build, you can...
A constexpr non-static member function isn't required to be implicitly const.C++ Ikkopja constexpr float exp(float x, int n) { return n == 0 ? 1 : n % 2 == 0 ? exp(x * x, n / 2) : exp(x * x, (n - 1) / 2) * x; } Suġġe...
When a nonstatic member function that is not a constructor is declared with theconstexprspecifier, that member function is constant, and theconstexprspecifier has no other effect on the function type. The class of which that function is a member must be a literal type. ...