How to "set the origin" of a Transform in sfml - c++

Question

I have a problem using sfml where it seems sf::Transforms get applied relative to the origin of whole coordinate system and not the origin of the sprite/thing being transformed.
For example in the two following example I expect the same behavior and it's not what happens.
(differences in bold, most of rest just serves to actually display a sfml window with a circle that gets scaled down when space is pressed)
First Example : here the circle is scaled down towards the top left corner of the window
#include &ltSFML/Graphics.hpp&gt
int main()
{
sf::RenderWindow window(sf::VideoMode(800, 800), "Example");
sf::CircleShape shape(100.f);
shape.setFillColor(sf::Color::Green);
shape.setPosition(400, 400);
sf::Transform t;
t.scale( 9/10.f , 9/10.f);
sf::Transform t_n;
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::Closed){
window.close();
}
if (event.type == sf::Event::KeyPressed) {
if (event.key.code == sf::Keyboard::Space) {
t_n = t_n * t;
}
}
}
window.clear();
window.draw(shape, t_n);
window.display();
}
return 0;
}
Second Example : Here the circle is scaled down towards the top left corner of its bounding box : this is the kind of behavior I want to achieve but using Transforms
#include &ltSFML/Graphics.hpp&gt
int main()
{
sf::RenderWindow window(sf::VideoMode(800, 800), "Example");
sf::CircleShape shape(100.f);
shape.setFillColor(sf::Color::Green);
shape.setPosition(400, 400);
// no Transforms need declaring
while (window.isOpen())
{
sf::Event event;
while (window.pollEvent(event))
{
if (event.type == sf::Event::Closed){
window.close();
}
if (event.type == sf::Event::KeyPressed) {
if (event.key.code == sf::Keyboard::Space) {
shape.scale(9/10.f, 9/10.f);
}
}
}
window.clear();
window.draw(shape);
window.display();
}
return 0;
}
note: this is a possible duplicate of Transformations igrnores sf::Sprite's origin , but the only answer to this thread is my own, and the solution I suggest is really not ideal.