There is an obsession in France about the problem of housing the "working class," or poor people. This is strange to someone coming from America, where there is very little recognition of the existence of the homeless. What exists in America though is a heightened awareness of racial equality, so no one group is ever deliberately isolated. Whereas Americans discriminate against the poor people as a whole, the French, it seems, find people such as the pied noirs unbearable.
For decades, the French have experimented with logements sociale, in an effort to "integrate" the immigrants, or at least to lure them out of Paris. Here are two old cartoons I found at a stall along the Seine. They depict some radical modernist plans for France and Paris respectively.