int main () {
std::pair <std::string, double> product1; // default constructor
std::pair <std::string, double> product2("tomatoes", 2.30); // value init
std::pair <std::string, double> product3(product2); // copy constructor
product1 = std::make_pair(std::string("lightbulbs"), 0.99); // using make_pair (move)
product2.first = "shoes"; // the type of first is string
product2.second = 39.90; // the type of second is double
std::cout << "The price of " << product1.first << " is $" << product1.second << '\n';
std::cout << "The price of " << product2.first << " is $" << product2.second << '\n';
std::cout << "The price of " << product3.first << " is $" << product3.second << '\n';
return 0;
}
NativeView(JNIEnv *_env, jobject _obj, unsigned _width, unsigned _height,
unsigned _sdk_version, jstring _product)
:env(_env), obj(env, _obj),
width(_width), height(_height), sdk_version(_sdk_version) {
Java::String product2(env, _product);
product2.CopyTo(env, product, sizeof(product));
Java::Class cls(env, "org/xcsoar/NativeView");
init_surface_method = env->GetMethodID(cls, "initSurface", "()Z");
deinit_surface_method = env->GetMethodID(cls, "deinitSurface", "()V");
setRequestedOrientationID =
env->GetMethodID(cls, "setRequestedOrientation", "(I)Z");
swap_method = env->GetMethodID(cls, "swap", "()V");
load_resource_texture_method = env->GetMethodID(cls, "loadResourceTexture",
"(Ljava/lang/String;[I)Z");
load_file_texture_method = env->GetMethodID(cls, "loadFileTexture",
"(Ljava/lang/String;[I)Z");
}
VEC *iter_lanczos2(ITER *ip, VEC *evals, VEC *err_est)
#endif
{
VEC *a;
STATIC VEC *b=VNULL, *a2=VNULL, *b2=VNULL;
Real beta, pb_mant, det_mant, det_mant1, det_mant2;
int i, pb_expt, det_expt, det_expt1, det_expt2;
if ( ! ip )
error(E_NULL,"iter_lanczos2");
if ( ! ip->Ax || ! ip->x )
error(E_NULL,"iter_lanczos2");
if ( ip->k <= 0 )
error(E_RANGE,"iter_lanczos2");
a = evals;
a = v_resize(a,(unsigned int)ip->k);
b = v_resize(b,(unsigned int)(ip->k-1));
MEM_STAT_REG(b,TYPE_VEC);
iter_lanczos(ip,a,b,&beta,MNULL);
/* printf("# beta =%g\n",beta); */
pb_mant = 0.0;
if ( err_est )
{
pb_mant = product(b,(double)0.0,&pb_expt);
/* printf("# pb_mant = %g, pb_expt = %d\n",pb_mant, pb_expt); */
}
/* printf("# diags =\n"); v_output(a); */
/* printf("# off diags =\n"); v_output(b); */
a2 = v_resize(a2,a->dim - 1);
b2 = v_resize(b2,b->dim - 1);
MEM_STAT_REG(a2,TYPE_VEC);
MEM_STAT_REG(b2,TYPE_VEC);
for ( i = 0; i < a2->dim - 1; i++ )
{
a2->ve[i] = a->ve[i+1];
b2->ve[i] = b->ve[i+1];
}
a2->ve[a2->dim-1] = a->ve[a2->dim];
trieig(a,b,MNULL);
/* sort evals as a courtesy */
qsort((void *)(a->ve),(int)(a->dim),sizeof(Real),(int (*)())dbl_cmp);
/* error estimates */
if ( err_est )
{
err_est = v_resize(err_est,(unsigned int)ip->k);
trieig(a2,b2,MNULL);
/* printf("# a =\n"); v_output(a); */
/* printf("# a2 =\n"); v_output(a2); */
for ( i = 0; i < a->dim; i++ )
{
det_mant1 = product2(a,i,&det_expt1);
det_mant2 = product(a2,(double)a->ve[i],&det_expt2);
/* printf("# det_mant1=%g, det_expt1=%d\n",
det_mant1,det_expt1); */
/* printf("# det_mant2=%g, det_expt2=%d\n",
det_mant2,det_expt2); */
if ( det_mant1 == 0.0 )
{ /* multiple e-val of T */
err_est->ve[i] = 0.0;
continue;
}
else if ( det_mant2 == 0.0 )
{
err_est->ve[i] = HUGE_VAL;
continue;
}
if ( (det_expt1 + det_expt2) % 2 )
/* if odd... */
det_mant = sqrt(2.0*fabs(det_mant1*det_mant2));
else /* if even... */
det_mant = sqrt(fabs(det_mant1*det_mant2));
det_expt = (det_expt1+det_expt2)/2;
err_est->ve[i] = fabs(beta*
ldexp(pb_mant/det_mant,pb_expt-det_expt));
}
}
#ifdef THREADSAFE
V_FREE(b); V_FREE(a2); V_FREE(b2);
#endif
return a;
}
