remove library() call from try_require(). closes #3126.

Author: clauswilke

R/fortify-map.r

@@ -75,7 +75,7 @@ fortify.map <- function(model, data, ...) {
 #'   coord_map("albers",  at0 = 45.5, lat1 = 29.5)
 #' }
 map_data <- function(map, region = ".", exact = FALSE, ...) {
-  try_require("maps", "map_data", attach = TRUE)
+  try_require("maps", "map_data")
   map_obj <- maps::map(map, region, exact = exact, plot = FALSE, fill = TRUE, ...)
   fortify(map_obj)
 }

R/stat-quantile.r

@@ -54,9 +54,6 @@ StatQuantile <- ggproto("StatQuantile", Stat,
 
     if (is.null(formula)) {
       if (method == "rqss") {
-        # this should not be needed, since quantreg imports MatrixModels
-        # try_require("MatrixModels", "stat_quantile")
-
         # we need to attach quantreg for qss to work inside formula
         require("quantreg")
         formula <- eval(substitute(y ~ qss(x, lambda = lambda)),

R/utilities.r

@@ -47,13 +47,8 @@ clist <- function(l) {
 # the name of the ggplot2 function that uses this package, and is
 # used only to produce a meaningful error message if the
 # package is not available.
-#
-# Set `attach = TRUE` if you want to attach the package, not
-# just make sure it is available. It is generally recommended to
-# not set `attach = TRUE`.
-try_require <- function(package, fun, attach = FALSE) {
+try_require <- function(package, fun) {
   if (requireNamespace(package, quietly = TRUE)) {
-    if (isTRUE(attach)) library(package, character.only = TRUE)
     return(invisible())
   }