vs下编译没有问题，g++下提示错误(pdfium)

#include <iostream>
namespace v8 {
 
    namespace internal {
        enum FunctionKind {
            kNormalFunction = 0,
            kArrowFunction = 1,
            kGeneratorFunction = 2,
            kConciseMethod = 4,
            kConciseGeneratorMethod = kGeneratorFunction | kConciseMethod,
            kDefaultConstructor = 8,
            kDefaultConstructorCallSuper = 16
        };
        inline bool IsValidFunctionKind(FunctionKind kind) {
            return kind == FunctionKind::kNormalFunction ||
                kind == FunctionKind::kArrowFunction ||
                kind == FunctionKind::kGeneratorFunction ||
                kind == FunctionKind::kConciseMethod ||
                kind == FunctionKind::kConciseGeneratorMethod ||
                kind == FunctionKind::kDefaultConstructor ||
                kind == FunctionKind::kDefaultConstructorCallSuper;
        }
 
        inline bool IsArrowFunction(FunctionKind kind) {
 
            return kind & FunctionKind::kArrowFunction;
        }
 
 
        inline bool IsGeneratorFunction(FunctionKind kind) {
 
            return kind & FunctionKind::kGeneratorFunction;
        }
 
 
        inline bool IsConciseMethod(FunctionKind kind) {
 
            return kind & FunctionKind::kConciseMethod;
        }
 
 
        inline bool IsDefaultConstructor(FunctionKind kind) {
 
            return kind & FunctionKind::kDefaultConstructor;
        }
 
 
        inline bool IsDefaultConstructorCallSuper(FunctionKind kind) {
 
            return kind & FunctionKind::kDefaultConstructorCallSuper;
        }
 
}
 
}
namespace i = v8::internal;
int main()
{
    std::cout << "Hello World!\n"; 
    system("PAUSE");
}